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

Annotations already indicate idempotent and non-destructive behavior. The description adds the no-OCR limitation, the optional pages behavior, and the credit cost, which are not captured elsewhere. No contradiction with annotations.

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 concise sentences pack the core purpose, a key limitation, optional behavior, and cost. No fluff; the most critical info (no OCR) is front-loaded.

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 extraction tool with two parameters and no output schema, the description tells the agent everything needed to decide and invoke: what it returns, the limitation, the optional flag, and the cost.

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 covers both parameters fully (100% coverage). The description adds a brief note about pages=true returning page-by-page text, but this is a minor elaboration beyond the schema's own descriptions.

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?

Clearly states the verb 'extract' and resource 'text of a PDF', and explicitly distinguishes from scanned images via 'not scanned images: there is no OCR'. This sets it apart from sibling PDF tools like pdf_to_images or merge_pdfs without requiring schema inspection.

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?

Provides a clear exclusion condition (no OCR for scanned images), telling the agent when NOT to use this tool. It doesn't name a specific alternative, but the limitation is explicit and actionable.

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