fetch_document

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

With no annotations, the description carries the behavioral disclosure burden. It reveals that responses are hard-capped at max_tokens and that page length can make whole-page retrieval impractical. It could mention continuation or failure behavior, but the output schema and max_tokens parameter partially cover that.

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?

Three sentences, all substantive: purpose, usage trigger, and a concrete recommendation. No filler, no repetition, and the core information is front-loaded in the first sentence.

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?

Given a full output schema and 100% parameter documentation, the description supplies the essential invocation context: when to call, how to choose between page and section, and the response cap. It does not discuss alternatives like list_related or compare_versions, but those are less relevant to correctly invoking this tool.

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 schema already documents all four parameters with 100% coverage, so the baseline is 3. The description adds meaning beyond the schema by naming the source of ref, explaining why section is preferable, and highlighting the practical consequence of max_tokens.

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?

States the exact operation: retrieve the full text of a documentation page or one section by ref. It explicitly ties ref to search_docs results, distinguishing this tool from the search_docs sibling and other documentation tools.

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?

Gives an explicit trigger: use when a search passage is clearly relevant but cut off mid-explanation or mid-code-block. It also advises preferring the section parameter because whole pages can be long and output is hard-capped at max_tokens.

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