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

Annotations already declare readOnlyHint=true, idempotentHint=true and openWorldHint=false, so the safety profile is covered. The description adds real value beyond that by disclosing the shape of the payload, notably that retailers are returned as names only with no links, plus the presence of provenance and a last-checked timestamp. It stops short of stating what happens for an unknown id or whether any field can be absent.

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?

A single dense sentence with the operation front-loaded and the return contents ordered after it. Every clause adds information and nothing is repeated from the name, title, or annotations.

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 does the work of enumerating return fields and even flags the names-only limitation on retailer data, and annotations cover the read-only/idempotent profile. The only gap is error or not-found behavior for an invalid id, which an agent might reasonably want to know.

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?

The single 'id' parameter is an undocumented string in the schema (0% coverage), so the description carries the burden of explaining its origin, which it does by pointing to find_gear as the source of valid ids. That is meaningful semantics beyond the schema, though it gives no format hints (opaque token vs. slug) or validation behavior.

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 ('Returns the full record for one item by id') and enumerates exactly what the record contains (specs, fit fields, why/why not, evidence links, retailers, provenance, last-checked). It also distinguishes itself from the sibling find_gear by noting where ids originate, so an agent can place it in the workflow without opening the schema.

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 rather than stated: 'ids come from find_gear' tells the agent this is the follow-up step to a search, and the sibling 'compare' is never mentioned. There is no explicit when-not or alternative-selection rule, so the agent must infer that this is a per-id detail lookup versus a multi-item comparison.

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