pdf_merge

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description must fully convey behavior. It does not state whether files are accepted as local paths, base64, or both; nor does it explain what happens when outputPath is omitted (e.g., where the result goes). Critical behavioral details are missing.

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 sentence that fronts the core purpose. Every word is necessary, with no redundancy or filler.

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?

Given that there is no output schema, the description should clarify return behavior (e.g., saved file or stream), error handling, and file constraints. It does not, leaving the agent with incomplete information for a tool that merges files.

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?

Schema description coverage is 100% (both parameters have descriptions). The tool description does not add extra meaning beyond what the schema already provides, so a 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 'Merge multiple PDF files into a single PDF document' clearly states the action (merge), object (PDF files), and result (single PDF). It distinguishes this tool from siblings like pdf_split (splits) and pdf_convert (converts format).

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 the use case (combining PDFs) but provides no explicit guidance on when to use this tool versus alternatives (e.g., pdf_split or image_merge). No 'use when' or 'use instead' context is given.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.