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

readOnlyHint=true already declares the safety profile; 'Non-mutating computation' restates it, though it usefully clarifies that a POST endpoint does not mutate state. The Engine API endpoint (POST /rationale) is genuine added context. No return-shape, pagination, or auth detail is provided.

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?

Three tight sentences, front-loaded with the core purpose before the implementation detail. Every sentence earns its place with no filler.

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 6-param tool with nested evidence objects and no output schema, the description is thin: it conveys the intent of the return ('explain WHY') but not the shape of the response or the evidence payload expectations. Adequate but leaves gaps an agent must resolve elsewhere.

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 83%, so the schema already documents age, sex, evidence, model_id, dev_mode, and extras. The description adds no parameter syntax or format detail beyond that, so the baseline 3 applies.

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+resource: explaining why the engine wants its next question, scoped to given evidence. This is distinguishable from diagnosis/triage at a glance. However it never names which sibling it differs from (e.g. infermedica_explain or infermedica_suggest), so the differentiation is inferred 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?

Implies the precondition 'given the evidence' but gives no explicit when-to-use, when-not-to-use, or alternative tool. With 17 siblings including explain/suggest/diagnosis, an agent gets no routing guidance on why to pick this over those.

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