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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: exact path matching, per-library path shape variation, and that the return is current markdown. It stops short of error/failure behavior but is strong for a read tool whose safety is already annotated.

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 tight sentences, front-loaded with what it does, then the exact-match constraint, then the routing instruction. Every sentence carries actionable information with no padding.

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 2-parameter read tool with full schema coverage and annotations covering safety, this is complete: it states the return format (markdown), the strict input provenance, and the prerequisite alternative tool. Nothing an agent needs to invoke 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 coverage is 100%, so the baseline is 3, but the description adds real meaning: take lib and path 'verbatim' from a search hit, paths are matched exactly, and their shape differs per library so they must never be guessed or adapted. This clarifies the required provenance and validation behavior beyond the schema's field 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?

States a specific verb and resource ('Read one documentation page in full, as current markdown') and implicitly distinguishes itself from search_docs and get_example by being the full-page reader. An agent can tell what it does and how it differs from retrieval/search siblings.

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?

Explicitly routes the agent: 'Call search_docs first when you do not have a path yet.' It also names the docs://{lib}/index resource as an alternative source of lib/path, giving clear when-to-use guidance with no inference required.

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