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

Annotations already declare readOnlyHint and closed-world openWorldHint, so the safety profile is covered. The description adds real value by disclosing that thrust and VTX tables exist only "where measured"/"where published" and that sources and caveats are included, priming the agent for partial or qualified data. It omits not-found/error behavior.

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?

One sentence, front-loaded with the action and resource, then a colon-list of return contents and a parenthetical example placed exactly where the ambiguous term appears. Nothing is padded.

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?

With no output schema, the description carries the burden of describing the return payload and does so concretely, plus annotation-covered safety. For a 2-parameter read-only lookup this is sufficient to invoke correctly.

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 50%, with `slug` undocumented in the schema — the description compensates well by defining it as the last URL segment and giving a worked example. The optional `type` enum parameter is not addressed at all, leaving unclear whether supplying it changes resolution or is merely advisory.

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 full spec sheet of one part by its slug" is a specific verb+resource, and the enumerated return contents (specs, bench thrust table, VTX table, sources, caveats) make the scope unambiguous. It never names search_parts, so the contrast with the sibling is inferred from the singular scope rather than stated.

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?

Usage is implied: call it when you already hold a part slug. The URL-derivation hint helps, but there is no explicit "use this instead of search_parts when..." routing or note on what to do when the slug is unknown.

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