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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description adds genuinely new behavior: the exact stylistic contract, that medical content comes only from published guidelines, and that triage runs first (a safety ordering guarantee). This is real context beyond the structured fields.

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?

Purpose is front-loaded in the first sentence, usage routing sits in the second paragraph, and every clause carries information (audience, ages, format, sourcing, audience segments). Slightly dense but 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?

With an output schema present, return values need no explanation, and the description covers audience, style contract, sourcing constraints, triage ordering, and alternative-tool routing. Nothing an agent needs to call this correctly is missing.

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 100%, so lang, country, and question are already documented with enum, pattern, and length constraints. The description adds the useful 'eight languages' fact matching the lang enum, but nothing else about parameter syntax or behavior. Baseline 3 is appropriate when the schema does the heavy lifting.

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 specific transformation (a sourced answer rewritten to be read aloud to a child aged 5-10) with concrete output characteristics: three to five warm sentences, no frightening words, one comparison, one action. It is instantly distinguishable from paediatric_question_with_sources, which it explicitly names.

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?

It gives an explicit when: 'Use when the answer will be read by or to a child aged 5 to 10.' It then names the alternative and its condition: 'For the parent's own question use paediatric_question_with_sources.' No inference is required.

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