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

The description does not mention the async capability (async parameter and webhook_url) or that results can be polled via check-job-status. Annotations already declare readOnlyHint=true, but the description adds no further behavioral context beyond the basic read operation.

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?

A single, well-structured sentence that immediately states the tool's purpose. No extraneous words.

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 read-only tool with 3 parameters and no output schema, the description covers the core functionality. It could mention the async option, but overall it is adequate.

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 coverage is 100% with descriptions for each parameter. The description adds value by listing example metadata fields (title, author, page count, file size) that are not in the schema, giving the user a sense of what the output contains.

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 ('Read') and resource ('metadata from a PDF file') and lists example fields (title, author, page count, file size). It clearly distinguishes from sibling tools like read-pdf-content or search-pdf-content.

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?

No explicit when-to-use or when-not-to-use guidance is provided. The purpose is implicitly clear from the name and description, but there is no direct comparison to siblings like read-pdf-content.

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