WHO-5 well-being score

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

Annotations already declare readOnlyHint, idempotentHint and non-destructive behavior, so the safety profile is covered. The description adds genuinely non-obvious context: the score band cutoffs (28 or less / 29 to 50 / normal) and the clinical caveat that the score is not a diagnosis. It stops short of explaining how the raw 0-5 sum scales to 0-100, but the scoring behavior is otherwise well disclosed.

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?

Five short sentences with the purpose first, then the trigger condition, then the input format, then the return shape, then the safety caveat. Nothing is repeated and no sentence could be dropped without losing a distinct fact.

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 single-parameter scoring tool with an output schema and full annotation coverage, the description supplies everything still missing: input scaling anchors, band thresholds, and the clinical-use exclusion. No gap remains that would cause a misinvocation.

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 coverage is 100% and already constrains the array to five integers of 0-5, so the baseline would be 3. The description earns above baseline by supplying the response anchors ('0 at no time' to '5 all of the time') and stressing item order, meaning an agent would not reverse-scale or reorder the answers.

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 ('Scores the WHO-5 Well-Being Index') and immediately scopes it to the exact input the tool consumes. An agent knows precisely what the tool produces and what it needs 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?

Gives an explicit when-to-use condition ('user has answered the five WHO-5 items about the last two weeks and wants their score') and an explicit when-not-to-use boundary ('Do not use it for symptoms, illnesses or medication'). No sibling tools exist, so no alternative routing is needed.

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