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

Annotations already cover the read-only, idempotent, non-destructive profile, so the description's job is to add behavior — and it does: server-side filtering on the 'why' and 'title' fields and a hard cap of 5 returned matches. What it doesn't say is how the 'best-fit' ranking works or whether concept matching is fuzzy or semantic, which keeps it below 5.

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 tight sentences, front-loaded with the purpose and the example query before the mechanics. The phrase 'filters server-side on why + title' is cryptic (field names 'why'/'title' are asserted without explanation), a small clarity cost in an otherwise efficient definition.

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?

No output schema exists, so the description should indicate what a 'match' looks like; it only says up to 5 are returned, not their fields or ordering. Combined with the undocumented 'forVersion' parameter, an agent knows roughly what it will get but not how to shape the version input or read the response.

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 0% and both parameters are required, so the description must carry the burden. It effectively illustrates 'concept' via the sample query, but 'forVersion' is never mentioned — no format, no hint about which version scheme to pass — leaving a required parameter entirely undocumented.

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 says it returns best-fit examples for a free-form concept query, with an illustrative query ("how do I use effects?"), which distinguishes it from the sibling examples_list (a plain listing). It never uses a direct verb like 'search' or 'find', so the retrieval action is implied rather than stated, but the resource and result type are unambiguous.

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 example query implies the tool is for natural-language 'how do I...' style questions rather than exact identifiers, which is useful implied usage guidance. However, it gives no explicit when-to-use/when-not guidance and never names an alternative (e.g., docs_search, examples_list, stdlib_search), so an agent must infer routing from context alone.

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