pdf_merge

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

With no annotations, the description carries the full burden, and it does add useful context: local paths, ordered input, and a per-operation cost of 1 cent. However, it does not clarify overwrite behavior, what happens to the original files, or how the merged result is delivered.

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 extremely short and front-loaded. The core action comes first, followed by the key parameter detail and cost, with no filler 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 merge operation, the description covers the main input and pricing, but it leaves the optional `output_path` and `idempotency_key` semantics unexplained. Given that there is no output schema and no annotations, an agent still lacks some information needed to understand the full contract.

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 description adds value for the `files` parameter by reinforcing local paths and ordering, but it says nothing about `output_path` or `idempotency_key`. Since schema description coverage is only 33%, the description must compensate for those undocumented parameters, and it does not.

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 states a specific verb and resource: merging two or more PDFs into one. It also specifies local paths and ordering, which makes the tool distinct from siblings like pdf_split and pdf_compress.

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 intended use case is clear: combining multiple local PDFs in a specific order. It doesn't explicitly spell out when not to use it or mention alternatives, but the context is unambiguous enough for an agent to select it over siblings.

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