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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds real behavior beyond that: the `includeAll=true` query flag signals that no weigh-ins are filtered out, and the endpoint path confirms it is a pure read against the weigh-in day view. It stops short of covering return shape, ordering, or empty-result behavior.

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 short, front-loaded sentences with no filler; the scope statement comes first. The raw URL template is borderline noise the agent can't act on, which keeps it out of 5 territory.

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 one-parameter read tool whose annotations cover safety, the essentials are present, but there is no output schema and the description does not characterize what a weigh-in record contains or what happens when no weigh-ins exist on the date. That leaves the return contract unspecified.

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 cdate is fully documented as YYYY-MM-DD UTC in the schema, so the schema carries the load. The description's only contribution is restating the placeholder as `{cdate}` in the URL, adding no new semantics such as timezone handling or the meaning of the returned date bucket.

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 scope: all weigh-ins recorded on exactly one date, which implicitly distinguishes it from get_weigh_ins (range) and the add_/delete_ weigh-in siblings. It never names an alternative sibling, so the differentiation is only inferable from the singular-date scoping.

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 prerequisite or alternative is named. The reader must infer from 'one date' that get_weigh_ins is the range counterpart; nothing in the text routes the agent.

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