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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds behavioral context beyond annotations by explaining the two modes (index vs. page) and the slug format requirement (path after /docs/ without .md). It doesn't mention rate limits or response size, but for a read-only docs tool the added context is sufficient.

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 compact and front-loaded: it states the core function first, then explains the two modes, gives examples, and ends with usage guidance. Every sentence earns its place with no redundancy or filler.

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 one optional parameter and no output schema, the description is complete. It explains the two invocation modes, the slug format, provides examples, and states when to use the tool. The annotations cover the safety profile, and the schema covers the parameter. Nothing an agent needs to call it correctly is 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?

Schema description coverage is 100%, so the schema already documents the slug parameter. The description adds value by explaining the slug format precisely (path after /docs/ without .md) and providing concrete examples, plus clarifying that omitting it returns the index. This goes beyond the schema's generic 'Page slug like...' description.

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 clearly states the tool reads Ray's documentation as markdown, with a specific verb and resource. It distinguishes itself from siblings by being the documentation lookup tool, and explicitly says to use it for anything the tool descriptions don't cover, which differentiates it from the other API 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?

The description provides explicit usage guidance: with no slug it returns the index, and with a slug it returns a specific page. It also gives concrete examples of valid slugs and states when to use it ('for anything the tool descriptions don't cover'), which is clear context for when to invoke this tool over alternatives.

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