add_weigh_in_with_timestamps

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

Annotations only say readOnlyHint=false, openWorldHint=true, destructiveHint=false. The description adds substantive behavior beyond that: values are stored raw with no unit conversion, supplied timestamp strings are re-formatted rather than forwarded verbatim, and omitted `gmtTimestamp` is derived from the resolved instant. This is real disclosure for a mutation tool, though it says nothing about auth or failure 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?

It is compact and wastes no sentences, but it is not front-loaded: the purpose is deferred behind a reference to another tool, and the content is crammed into one dense paragraph with nested parentheticals. Efficient but not well-ordered for fast scanning.

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 mutation tool with five parameters, no output schema, and only 20% schema coverage, the hardest part (coupled timestamp resolution) is covered well. However, the unit/weight relationship and any notion of what the call returns or how success/failure manifests are absent, leaving gaps an agent would otherwise have to guess at.

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 20%, so the description must carry the burden, and it largely does: it clarifies `dateTimestamp` vs `when` precedence, naive-string interpretation (LOCAL for dateTimestamp, UTC for gmtTimestamp), the default of `new Date()`, and the derivation of `gmtTimestamp`. It leaves `weightValue` and `unitKey` unexplained beyond the passing 'raw-value, no-conversion' rule.

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 never states plainly that it records a weigh-in; it opens with an anaphoric reference ('same raw-value, no-conversion rule as `addWeighIn`') that assumes knowledge of a sibling. Combined with the name, an agent can infer the purpose, but the description is not self-contained and leans on comparison rather than stating verb+resource directly.

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?

It references `addWeighIn` but gives no explicit guidance on when to choose this timestamped variant over the plain `add_weigh_in` sibling, which is the central routing decision for this tool. No prerequisites, no exclusions, no conditions are stated.

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