pdf_merge

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

No annotations are provided, so the description carries the full burden. It discloses that merging preserves the given order and that the result is saved, but it does not mention whether the output file is overwritten, whether input files are affected, or how errors are handled. These are notable gaps for a file-writing tool.

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, well-structured sentence that front-loads the action and includes the key ordering constraint. There is no wasted text or redundancy.

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?

For a simple two-parameter merge tool, the description covers the core behavior and the schema documents the parameters. However, with no annotations and no output schema, a few behavioral details such as overwrite behavior and error handling are missing, though they are relatively minor for this operation.

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%, so the schema already fully documents both parameters. The description adds no new parameter-specific detail beyond restating what the schema says ('in order' and 'save the result'), so the baseline 3 applies.

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 uses a specific verb ('Merge') with a clear resource ('PDFs') and explains the outcome ('save the result'). It also specifies the order-sensitive nature, which helps distinguish it from sibling tools like pdf_inspect or pdf_fill that operate on PDFs differently.

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 usage when combining multiple PDFs, but it provides no explicit when-to-use guidance or comparison with alternatives. Since sibling tools cover different PDF operations, a note on when to choose merge over others would have been helpful.

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