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

The annotations already record readOnlyHint=true and destructiveHint=false, and the description reinforces this with 'Read-only — no mutation (curator-policy D4)'. It also adds meaningful behavioral detail: the composite-score ranking formula and available filters. No contradiction with 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?

Two sentences with no filler: purpose and ranking are front-loaded, filters are listed compactly, and the read-only note closes the description. Every clause adds useful information.

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?

Given the presence of an output schema, not detailing return values is acceptable. The description covers purpose, ranking, filters, and safety. The only meaningful gap is the lack of explicit sibling-tool routing and the unexplained limit parameter, but these are minor relative to the schema and annotation richness.

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%, so the description needs to compensate. It names three optional filters (min_reliability, cross_cultural_only, length_lte) and implies construct_id via 'given construct', which adds some guidance. However, it does not explain the semantics, ranges, or units of those filters, and it omits the limit parameter entirely.

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 names a concrete operation ('Return instruments'), a specific scope ('that measure a given construct'), and a ranking scheme ('composite score'). This is clear and distinguishes the tool from generic list/lookup siblings, though it does not explicitly name a sibling alternative.

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 natural use case is implied: when you have a construct and want measurement instruments, optionally filtered. However, it does not explicitly say when to prefer this over instruments.search or constructs.search, nor does it state exclusions or alternatives. Usage guidance is mostly inferential.

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