write_goal_weight

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

Annotations already declare destructiveHint=true and openWorldHint=true, so the safety profile is covered. The description adds substance beyond that: null deletes the target, and openGym merges settings per-setting so a later conflicting device write wins if it syncs first — a non-obvious conflict-resolution rule.

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, front-loaded with the core action and the null-clearing behavior. The second sentence is dense and slightly cryptic, but it is not padded boilerplate.

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 single-parameter mutation with no output schema and 0% schema coverage, the description covers value semantics, units, the clear case, and the merge/overwrite rule. Return value or confirmation behavior is unspecified, which is a minor gap.

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 0% and the single parameter is undocumented in the schema, so the description carries the burden. It does add real meaning: the value is interpreted in the 'profile unit' (not a fixed unit), and null clears the goal rather than writing zero.

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: set the goal body weight (targetW) in the profile's unit, or clear it with null. That distinguishes it from siblings like write_bodyweight (actual weight) and write_settings, though it never names those siblings explicitly.

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 description makes the set-vs-clear choice explicit (numeric value vs null), which is genuine usage guidance. But it gives no when-to-use context relative to write_bodyweight/write_settings, and the trailing merge sentence doesn't tell an agent when to prefer this tool.

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