get_body_composition

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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered. The description adds one real behavioral fact — the 90-day default window — but says nothing about units, what happens on days with no weigh-in, or whether the average includes only recorded days.

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, the payload described first and the defaulting rule second, with no filler or redundancy.

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?

An output schema exists so return shape needn't be restated, and the description covers scope, metrics, aggregation, and the default window. That is everything an agent needs to call this read-only tool correctly.

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%, so the baseline is 3; the description earns an extra point by explaining that a null/omitted range defaults to the last 90 days, which the schema's 'default: null' does not convey.

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 resource (weigh-ins/body composition) and enumerates the returned metrics (weight, body fat, muscle, water, BMI) plus the range average, which clearly separates it from get_nutrition, get_recovery and the activity tools. It lacks an explicit verb like 'retrieve', but the intent is unambiguous.

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?

No when-to-use or when-not-to-use guidance and no mention of the sibling tools whose data overlaps (e.g. get_day_detail may also include weight). Usage is only implied by the metric list, which is adequate but leaves the agent to infer boundaries.

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