Merge multiple PDF documents into a single PDF
Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {
"pdfs": "<pdfs>"
},
"name": "merge_pdfs"
}
}| Name | Required | Description | Default |
|---|---|---|---|
| pdfs | Yes | Array of base64-encoded PDF strings to merge (2-100 PDFs) |
Changes observed during successful MCP inspections.
Input schema / properties / pdfs / descriptionPrevious value: -"Array of base64-encoded PDF strings to merge (2-20 PDFs)"New value: +"Array of base64-encoded PDF strings to merge (2-100 PDFs)"Input schema / properties / pdfs / maxItemsPrevious value: -20New value: +100Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are present, so the description carries the full burden. It only restates the core function and does not disclose whether input PDFs are modified, the output format, base64 handling, or error behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, front-loaded sentence with no redundancy or filler, making it maximally concise while conveying the essential purpose.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Although the schema covers the input fully, there is no output schema and the description does not explain the return value, possible errors, or side effects. The description alone is incomplete for a tool that produces a new PDF.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The single parameter 'pdfs' is fully described in the schema (array, base64-encoded, min/max items), and the tool description adds no additional meaning. With high schema coverage, the baseline score of 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action 'merge' applied to 'multiple PDF documents' and the outcome 'a single PDF', which is specific and distinguishes it from sibling tools like split_pdf and pdf_info.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description implies its use case (combining PDFs) but does not explicitly state when to use it over alternatives or mention exclusions or prerequisites. There is no guidance on when not to use it.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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