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 genuine behavioral context beyond annotations: results come back best-first with snippets and links, and a question not covered by the docs returns no results (meaning the answer is absent rather than approximate). This aligns with openWorldHint=false. It doesn't over-elaborate, and it doesn't contradict the 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?

The description is a single logical paragraph with a sensible flow: purpose → when to use → follow-up tool routing → no-results edge case. Every sentence carries weight, including the strong directive 'instead of answering from memory.' It's slightly long but well-organized and free of 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?

Complete for a search tool with only two simple parameters, no output schema, and rich annotations. The description covers purpose, usage conditions, the follow-up action (call gunspec_read_docs with guide and anchor), and the no-results semantic. The return format (sections with snippet and link) is stated even though no output schema exists, so nothing an agent needs 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% — both 'question' (with min/max length and 'in the user's own words') and 'limit' (with default of 8 and min/max range) are fully documented in the input schema. The description doesn't add parameter-specific meaning beyond what the schema already provides, so the baseline of 3 applies.

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 (searches) with a clearly identified resource (GunSpec documentation guides) and describes the output shape (sections ranked best-first, each with snippet and link). It clearly distinguishes itself from siblings like gunspec_read_docs (which reads a specific doc) and gunspec_search_firearms (which searches firearms rather than docs).

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 explicitly states when to use the tool — 'whenever the user asks how something works or how they should do something with GunSpec' — with concrete topic examples (rate limits, pagination, auth, webhooks, errors, pricing). It also names the follow-up tool (gunspec_read_docs) and instructs to use it instead of answering from memory. The negative case is also handled explicitly: no results means the answer isn't in the docs.

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