{ "title": "Annotate PDF", "human_url": "https://happytails.ai/en/pdf-tools/annotate-pdf/", "agent_url": "https://happytails.ai/agents/en/pdf-tools/annotate-pdf/", "language": "en", "markdown_url": "https://happytails.ai/en/pdf-tools/annotate-pdf.md", "content": "Annotate PDF\nAdd visible text to a PDF page.\nUseful next steps\nMerge PDF\nCombine PDF files into one document.\nSplit PDF\nSave selected PDF pages as separate files.\nExtract pages\nCreate a PDF containing the pages you select.\nHow to use Annotate PDF\nChoose a file in PDF.\nReview the settings, then choose Run Annotate PDF.\nReview the result, then use Copy result or a download link when available.\nWhat to expect\nAdd visible text to a PDF page. Enter the text, page number, font size, and position in PDF points. X is measured from the left and Y from the bottom. This adds text; it does not create secure redactions.", "content_format": "text/plain", "visibility": "public", "links": [ { "name": "Merge PDF Combine PDF files into one document.", "url": "https://happytails.ai/en/pdf-tools/merge-pdf/" }, { "name": "Split PDF Save selected PDF pages as separate files.", "url": "https://happytails.ai/en/pdf-tools/split-pdf/" }, { "name": "Extract pages Create a PDF containing the pages you select.", "url": "https://happytails.ai/en/pdf-tools/extract-pages/" } ], "tool": { "id": "annotate-pdf", "category": "pdf-tools", "built": true, "requirements": "Text, drawing, highlights and output persistence; distinguish annotation from editing existing text.", "implementation": { "fields": [ { "key": "page", "label": "Page", "value": 1, "type": "number" }, { "key": "x", "label": "X from left (points)", "value": 40, "type": "number" }, { "key": "y", "label": "Y from bottom (points)", "value": 40, "type": "number" }, { "key": "size", "label": "Text size", "value": 12, "type": "number" } ], "files": true, "accept": ".pdf", "note": "Adds visible text to a page. Coordinates are PDF points; this is not secure redaction or a digital signature.", "experience": { "automatic": false, "single": false, "label": "Your text", "placeholder": "Type or paste your input…", "help": "Up to 1,000,000 characters. Review the settings before running.", "action": null }, "mode": "explicit", "interactive": false }, "execution": "POST /api/v1/tools/annotate-pdf/run", "api": { "id": "annotate-pdf", "name": "Annotate PDF", "category": "pdf-tools", "description": "Add visible text to a PDF page.", "notes": "Adds visible text to a page. Coordinates are PDF points; this is not secure redaction or a digital signature.", "human_path": "/en/pdf-tools/annotate-pdf/", "method": "POST", "endpoint": "/api/v1/tools/annotate-pdf/run", "schema_url": "/api/v1/tools/annotate-pdf", "input_schema": { "type": "object", "additionalProperties": false, "properties": { "input": { "type": "string", "maxLength": 1000000, "default": "", "description": "Plain text input. File tools use files instead unless otherwise documented." }, "options": { "type": "object", "additionalProperties": false, "properties": { "page": { "type": "number", "description": "Page", "default": 1.0 }, "x": { "type": "number", "description": "X from left (points)", "default": 40.0 }, "y": { "type": "number", "description": "Y from bottom (points)", "default": 40.0 }, "size": { "type": "number", "description": "Text size", "default": 12.0 } } }, "files": { "type": "array", "maxItems": 1, "items": { "type": "object", "required": [ "name", "base64" ], "additionalProperties": false, "properties": { "name": { "type": "string", "maxLength": 200, "description": "Filename only, no path." }, "mime": { "type": "string", "maxLength": 150 }, "bytes": { "type": "integer", "minimum": 0, "description": "Optional decoded byte count; must match content if supplied." }, "base64": { "type": "string", "contentEncoding": "base64", "description": "File bytes as padded base64. Use the tool-specific limits.files_bytes value for the total decoded input size." } } } } } }, "output_schema": { "type": "object", "required": [ "tool", "result" ], "properties": { "tool": { "type": "string" }, "result": { "type": "object", "required": [ "text", "files" ], "properties": { "text": { "type": [ "string", "null" ] }, "data": { "description": "Parsed JSON when the textual result is JSON." }, "name": { "type": "string" }, "mime": { "type": "string" }, "files": { "type": "array", "items": { "type": "object", "required": [ "name", "mime", "bytes", "base64" ], "properties": { "name": { "type": "string" }, "mime": { "type": "string" }, "bytes": { "type": "integer" }, "base64": { "type": "string", "contentEncoding": "base64" } } } } } } } }, "processing": "Server; same transformation code as browser tools", "limits": { "request_bytes": 8388608, "input_characters": 1000000, "files_bytes": 5242880, "max_files": 1, "timeout_seconds": 12 } }, "agent_processing": "Server; same transformation code as browser tools", "browser_agent": { "supported": true, "name": "run_current_tool", "discovery": "WebMCP on the human page in a supporting browser", "verification": "See audit/API-AUDIT.md; availability is not verification" } }, "markdown": "# Annotate PDF\n\n- Human page: https://happytails.ai/en/pdf-tools/annotate-pdf/\n- Markdown: https://happytails.ai/en/pdf-tools/annotate-pdf.md\n- Structured JSON: https://happytails.ai/agents/en/pdf-tools/annotate-pdf/index.json\n- Visibility: public\n\n## Tool capabilities\n\n| Property | Value |\n| --- | --- |\n| Tool ID | `annotate-pdf` |\n| Category | pdf-tools |\n| Implementation | Registered implementation. Registration alone is not a production-quality guarantee. |\n| Browser execution | Use the visible action or interactive controls. |\n| Browser processing | Browser; see tool notes for network behavior. |\n| HTTP API | /api/v1/tools/annotate-pdf/run |\n| Browser-agent interface | run_current_tool |\n\n### Implementation notes\n\nAdds visible text to a page. Coordinates are PDF points; this is not secure redaction or a digital signature.\n\n### Inputs and settings\n\nText input: Your text.\n\nExample or placeholder shown in the interface (not a validated fixture):\n\n```text\nType or paste your input…\n```\n\nUp to 1,000,000 characters. Review the settings before running.\n\nAccepted browser files: `.pdf`. Choose one file.\n\n| Setting | Meaning | Control type | Default | Constraints |\n| --- | --- | --- | --- | --- |\n| `page` | Page | number | 1 | |\n| `x` | X from left (points) | number | 40 | |\n| `y` | Y from bottom (points) | number | 40 | |\n| `size` | Text size | number | 12 | |\n\n### HTTP contract\n\nAPI calls process supplied data on the server. The website origin is `https://happytails.ai`. Server API hosting is not connected on the public website yet. Use your local server origin to test these requests.\n\n```http\nPOST https://happytails.ai/api/v1/tools/annotate-pdf/run\nContent-Type: application/json\n```\n\n[Detailed operation reference](https://happytails.ai/en/api/tools/annotate-pdf.md) · [Shared API guide](https://happytails.ai/en/api.md)\n\n#### Limits\n\n| Limit | Value |\n| --- | --- |\n| request_bytes | 8388608 |\n| input_characters | 1000000 |\n| files_bytes | 5242880 |\n| max_files | 1 |\n| timeout_seconds | 12 |\n\n#### Complete input schema\n\n```json\n{\n \"type\": \"object\",\n \"additionalProperties\": false,\n \"properties\": {\n \"input\": {\n \"type\": \"string\",\n \"maxLength\": 1000000,\n \"default\": \"\",\n \"description\": \"Plain text input. File tools use files instead unless otherwise documented.\"\n },\n \"options\": {\n \"type\": \"object\",\n \"additionalProperties\": false,\n \"properties\": {\n \"page\": {\n \"type\": \"number\",\n \"description\": \"Page\",\n \"default\": 1.0\n },\n \"x\": {\n \"type\": \"number\",\n \"description\": \"X from left (points)\",\n \"default\": 40.0\n },\n \"y\": {\n \"type\": \"number\",\n \"description\": \"Y from bottom (points)\",\n \"default\": 40.0\n },\n \"size\": {\n \"type\": \"number\",\n \"description\": \"Text size\",\n \"default\": 12.0\n }\n }\n },\n \"files\": {\n \"type\": \"array\",\n \"maxItems\": 1,\n \"items\": {\n \"type\": \"object\",\n \"required\": [\n \"name\",\n \"base64\"\n ],\n \"additionalProperties\": false,\n \"properties\": {\n \"name\": {\n \"type\": \"string\",\n \"maxLength\": 200,\n \"description\": \"Filename only, no path.\"\n },\n \"mime\": {\n \"type\": \"string\",\n \"maxLength\": 150\n },\n \"bytes\": {\n \"type\": \"integer\",\n \"minimum\": 0,\n \"description\": \"Optional decoded byte count; must match content if supplied.\"\n },\n \"base64\": {\n \"type\": \"string\",\n \"contentEncoding\": \"base64\",\n \"description\": \"File bytes as padded base64. Use the tool-specific limits.files_bytes value for the total decoded input size.\"\n }\n }\n }\n }\n }\n}\n```\n\n#### Complete output schema\n\n```json\n{\n \"type\": \"object\",\n \"required\": [\n \"tool\",\n \"result\"\n ],\n \"properties\": {\n \"tool\": {\n \"type\": \"string\"\n },\n \"result\": {\n \"type\": \"object\",\n \"required\": [\n \"text\",\n \"files\"\n ],\n \"properties\": {\n \"text\": {\n \"type\": [\n \"string\",\n \"null\"\n ]\n },\n \"data\": {\n \"description\": \"Parsed JSON when the textual result is JSON.\"\n },\n \"name\": {\n \"type\": \"string\"\n },\n \"mime\": {\n \"type\": \"string\"\n },\n \"files\": {\n \"type\": \"array\",\n \"items\": {\n \"type\": \"object\",\n \"required\": [\n \"name\",\n \"mime\",\n \"bytes\",\n \"base64\"\n ],\n \"properties\": {\n \"name\": {\n \"type\": \"string\"\n },\n \"mime\": {\n \"type\": \"string\"\n },\n \"bytes\": {\n \"type\": \"integer\"\n },\n \"base64\": {\n \"type\": \"string\",\n \"contentEncoding\": \"base64\"\n }\n }\n }\n }\n }\n }\n }\n}\n```\n\n#### Error and retry handling\n\nFailures return a non-200 status and `error.code` plus `error.message`. Correct invalid input before retrying; retry server-busy responses with bounded backoff. Returned files contain Base64 data, not persistent download URLs. Decode and inspect the output before treating conversion as successful. See the shared API guide for the complete status and timeout rules.\n\n### Browser-agent workflow\n\n1. Open the human page in a browser that supports WebMCP.\n2. Discover the interface exposed by that page; use its actual schema.\n3. Select files on the page first when the tool requires files.\n4. Call `run_current_tool` with valid input and settings.\n5. Inspect the returned result or error and the displayed output. Retrieve files from the displayed download links.\n\nCalls do not automatically copy or download results. Browser permissions still apply. Interface availability alone is not proof of successful execution.\n\n### Planning specification\n\nText, drawing, highlights and output persistence; distinguish annotation from editing existing text.\n\nThis describes intended requirements. Use the implementation notes, interface schema and observed output to determine current support.\n\n### Complete machine-readable capability record\n\n```json\n{\n \"id\": \"annotate-pdf\",\n \"category\": \"pdf-tools\",\n \"built\": true,\n \"requirements\": \"Text, drawing, highlights and output persistence; distinguish annotation from editing existing text.\",\n \"implementation\": {\n \"fields\": [\n {\n \"key\": \"page\",\n \"label\": \"Page\",\n \"value\": 1,\n \"type\": \"number\"\n },\n {\n \"key\": \"x\",\n \"label\": \"X from left (points)\",\n \"value\": 40,\n \"type\": \"number\"\n },\n {\n \"key\": \"y\",\n \"label\": \"Y from bottom (points)\",\n \"value\": 40,\n \"type\": \"number\"\n },\n {\n \"key\": \"size\",\n \"label\": \"Text size\",\n \"value\": 12,\n \"type\": \"number\"\n }\n ],\n \"files\": true,\n \"accept\": \".pdf\",\n \"note\": \"Adds visible text to a page. Coordinates are PDF points; this is not secure redaction or a digital signature.\",\n \"experience\": {\n \"automatic\": false,\n \"single\": false,\n \"label\": \"Your text\",\n \"placeholder\": \"Type or paste your input…\",\n \"help\": \"Up to 1,000,000 characters. Review the settings before running.\",\n \"action\": null\n },\n \"mode\": \"explicit\",\n \"interactive\": false\n },\n \"execution\": \"POST /api/v1/tools/annotate-pdf/run\",\n \"api\": {\n \"id\": \"annotate-pdf\",\n \"name\": \"Annotate PDF\",\n \"category\": \"pdf-tools\",\n \"description\": \"Add visible text to a PDF page.\",\n \"notes\": \"Adds visible text to a page. Coordinates are PDF points; this is not secure redaction or a digital signature.\",\n \"human_path\": \"/en/pdf-tools/annotate-pdf/\",\n \"method\": \"POST\",\n \"endpoint\": \"/api/v1/tools/annotate-pdf/run\",\n \"schema_url\": \"/api/v1/tools/annotate-pdf\",\n \"input_schema\": {\n \"type\": \"object\",\n \"additionalProperties\": false,\n \"properties\": {\n \"input\": {\n \"type\": \"string\",\n \"maxLength\": 1000000,\n \"default\": \"\",\n \"description\": \"Plain text input. File tools use files instead unless otherwise documented.\"\n },\n \"options\": {\n \"type\": \"object\",\n \"additionalProperties\": false,\n \"properties\": {\n \"page\": {\n \"type\": \"number\",\n \"description\": \"Page\",\n \"default\": 1.0\n },\n \"x\": {\n \"type\": \"number\",\n \"description\": \"X from left (points)\",\n \"default\": 40.0\n },\n \"y\": {\n \"type\": \"number\",\n \"description\": \"Y from bottom (points)\",\n \"default\": 40.0\n },\n \"size\": {\n \"type\": \"number\",\n \"description\": \"Text size\",\n \"default\": 12.0\n }\n }\n },\n \"files\": {\n \"type\": \"array\",\n \"maxItems\": 1,\n \"items\": {\n \"type\": \"object\",\n \"required\": [\n \"name\",\n \"base64\"\n ],\n \"additionalProperties\": false,\n \"properties\": {\n \"name\": {\n \"type\": \"string\",\n \"maxLength\": 200,\n \"description\": \"Filename only, no path.\"\n },\n \"mime\": {\n \"type\": \"string\",\n \"maxLength\": 150\n },\n \"bytes\": {\n \"type\": \"integer\",\n \"minimum\": 0,\n \"description\": \"Optional decoded byte count; must match content if supplied.\"\n },\n \"base64\": {\n \"type\": \"string\",\n \"contentEncoding\": \"base64\",\n \"description\": \"File bytes as padded base64. Use the tool-specific limits.files_bytes value for the total decoded input size.\"\n }\n }\n }\n }\n }\n },\n \"output_schema\": {\n \"type\": \"object\",\n \"required\": [\n \"tool\",\n \"result\"\n ],\n \"properties\": {\n \"tool\": {\n \"type\": \"string\"\n },\n \"result\": {\n \"type\": \"object\",\n \"required\": [\n \"text\",\n \"files\"\n ],\n \"properties\": {\n \"text\": {\n \"type\": [\n \"string\",\n \"null\"\n ]\n },\n \"data\": {\n \"description\": \"Parsed JSON when the textual result is JSON.\"\n },\n \"name\": {\n \"type\": \"string\"\n },\n \"mime\": {\n \"type\": \"string\"\n },\n \"files\": {\n \"type\": \"array\",\n \"items\": {\n \"type\": \"object\",\n \"required\": [\n \"name\",\n \"mime\",\n \"bytes\",\n \"base64\"\n ],\n \"properties\": {\n \"name\": {\n \"type\": \"string\"\n },\n \"mime\": {\n \"type\": \"string\"\n },\n \"bytes\": {\n \"type\": \"integer\"\n },\n \"base64\": {\n \"type\": \"string\",\n \"contentEncoding\": \"base64\"\n }\n }\n }\n }\n }\n }\n }\n },\n \"processing\": \"Server; same transformation code as browser tools\",\n \"limits\": {\n \"request_bytes\": 8388608,\n \"input_characters\": 1000000,\n \"files_bytes\": 5242880,\n \"max_files\": 1,\n \"timeout_seconds\": 12\n }\n },\n \"agent_processing\": \"Server; same transformation code as browser tools\",\n \"browser_agent\": {\n \"supported\": true,\n \"name\": \"run_current_tool\",\n \"discovery\": \"WebMCP on the human page in a supporting browser\",\n \"verification\": \"See audit/API-AUDIT.md; availability is not verification\"\n }\n}\n```\n\n## Page guide\n\nAdd visible text to a PDF page.\n\n## Useful next steps\n\n- [Merge PDF](https://happytails.ai/en/pdf-tools/merge-pdf/): Combine PDF files into one document. ([Markdown](https://happytails.ai/en/pdf-tools/merge-pdf.md))\n\n- [Split PDF](https://happytails.ai/en/pdf-tools/split-pdf/): Save selected PDF pages as separate files. ([Markdown](https://happytails.ai/en/pdf-tools/split-pdf.md))\n\n- [Extract pages](https://happytails.ai/en/pdf-tools/extract-pages/): Create a PDF containing the pages you select. ([Markdown](https://happytails.ai/en/pdf-tools/extract-pages.md))\n\n## How to use Annotate PDF\n\n1. Choose a file in PDF.\n2. Review the settings, then choose Run Annotate PDF.\n3. Review the result, then use Copy result or a download link when available.\n\n## What to expect\n\nAdd visible text to a PDF page. Enter the text, page number, font size, and position in PDF points. X is measured from the left and Y from the bottom. This adds text; it does not create secure redactions.\n" }