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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds the identity caveat, which is genuine behavioral context, but the 'at most 10 QIDs' limit merely restates the schema's maxItems=10 and nothing is said about refresh semantics or return shape.

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 short, front-loaded sentences with no filler. It is efficient, though the second sentence is slightly cryptic and could have been spent on parameter meaning instead.

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 four-parameter tool with no output schema and zero schema-level parameter descriptions, the definition leaves lang, fields, and refresh entirely unexplained. An agent cannot confidently construct a call beyond the required qids array.

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% for four parameters, so the description must compensate and largely does not. It covers only the qids cap (already in maxItems) and says nothing about lang, fields, or refresh — notably refresh, whose behavior (cache invalidation?) is opaque.

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 action on a specific resource: compacting selected Wikidata facts for supplied QIDs, with a hard cap of 10. The clause 'Fact lookup does not establish local identity' hints at the boundary with the identity siblings (kg_audit_identity, kg_resolve), though it never names them. An agent can grasp the core purpose 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?

There is no explicit when-to-use guidance and no alternative tool is named. The single caveat ('does not establish local identity') implies a boundary with the identity/resolve siblings but leaves the agent to infer the routing rule. This is the weakest dimension.

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