PDF info

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

With no annotations, the description carries the full behavioral burden. It implicitly conveys a read-only inspection operation and discloses what is returned, which is helpful, but it says nothing about permissions, failure modes on encrypted files, or whether it mutates anything. Adequate but with real gaps.

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?

Two terse sentences that front-load the returned fields before the usage hint. Nothing is wasted, though the second sentence is so brief it borders on a fragment rather than substantive guidance.

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 one-parameter inspection tool with no output schema, the description usefully enumerates the return fields so the agent knows what to expect. Given the low complexity, this is close to complete, with only error/edge-case behavior missing.

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?

There is a single parameter, path, and the schema already documents it fully (absolute path required, relative refused) at 100% coverage. The description adds no parameter-level information, so the baseline of 3 for high schema coverage 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 names the resource (PDF) and enumerates the specific fields returned (page count, page sizes, encryption flag, metadata), which is more informative than a bare restatement of the title. However, it does nothing to distinguish itself from siblings like doc_read or pdf_edit, so a 4 rather than a 5.

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?

It offers one usage context, 'Use to verify a conversion,' which implies when the tool is useful. But it names no alternatives and gives no when-not guidance, leaving the agent to infer that doc_read or pdf_edit are the wrong choices for metadata inspection.

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