write_bodyweight

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

Annotations already flag destructiveHint=true; the description corroborates and enriches this by explaining exactly what is destroyed ('openGym keeps one weigh-in per day, so this replaces that day's entry'), which is the most important behavioral fact for a log tool. Auth requirements and return behavior are unaddressed, but the key destructive side effect is explicit.

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 tight sentences, zero filler, with the core action and its default front-loaded before the replace-behavior caveat.

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 two-parameter mutation with no output schema and annotations covering the safety profile, the description supplies the unit, the date default, and the overwrite semantics — the details an agent actually needs. Only the return value and any validation feedback are left implicit.

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 only 50% (weight has no schema description), and the description compensates by specifying the unit ('in the profile unit') for weight and the default ('default today') for date — neither of which the schema states. It stops short of discussing the allowed weight range enforced by the schema.

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 ('Log body weight for a day') and scopes it clearly enough to distinguish from read_bodyweight, delete_bodyweight, and write_measurement without opening any 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?

Explains the operational context an agent needs to decide to call it: 'default today' and the one-weigh-in-per-day rule that makes this a replace-style write. It doesn't explicitly name alternatives or exclusions, but the surrounding sibling set (read_bodyweight, delete_bodyweight) is unambiguous.

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