get_body_composition

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

Annotations already establish readOnlyHint=true and openWorldHint=true, so the safety profile is clear without the description. The description's one behavioral claim—that it defaults to the last 30 days—conflicts with the schema, where start and end both default to today, which could mislead an agent about the default scope.

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?

The description is a single front-loaded sentence with no filler. Every part of it contributes either the resource identity or the default range context.

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 and annotations present, the description need not explain return values or safety. Still, it is thin for selecting among many health-data siblings: it does not say whether this returns raw measurements, summaries, or how it relates to add_weigh_in or get_daily_summary.

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 schema already documents the start, end, and raw parameters thoroughly. The description adds only a default range statement, and that statement conflicts with the schema's documented defaults rather than clarifying parameter behavior.

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 clearly identifies the resource as weight and body composition entries, which lets an agent distinguish it from most sibling tools like get_sleep or get_hrv. It is slightly weaker than a 5 because it omits an explicit verb like 'retrieve' and does not explicitly contrast with add_weigh_in or get_daily_summary.

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 parenthetical default range gives useful context for what happens when no dates are supplied, implying the tool is for recent body composition history. However, it does not state when to use this tool versus get_daily_summary, get_profile, or add_weigh_in, nor does it describe any exclusions or prerequisites.

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