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

Annotations already declare the safe read-only, idempotent, non-destructive profile, so the description is free to add substantive behavior and does: it explains the effort-adjustment model (a runner is warmer than someone standing still at the same feels-like) and describes the output shape (short practical advice followed by the underlying weather). The opaque 'same rules as the website's outfit card' reference is the one weak spot.

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 front-loaded with the core purpose and kept to three sentences with no padding. The middle 'website's outfit card' clause is the only sentence that does not clearly earn its place.

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?

Despite 9 parameters (none required) and no output schema, the description tells the agent what comes back — practical advice plus the weather it depends on — and the schema fully documents every input including defaults and time-parsing behavior. Nothing essential to calling the tool correctly is missing, and the remaining gaps are minor.

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 description coverage is 100% and every parameter — including the nested preferences object, units, and time decoding rules — is already documented in the schema. The description only restates intensity and preference examples, adding little beyond that. Baseline 3 is correct when the schema does the heavy lifting.

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 states a specific verb+resource (what to wear) and scopes it to an activity, time, and place, with the outfit returned alongside the weather it rests on. It is clearly differentiated from weather siblings like get_forecast or outdoor_activity_weather because it produces clothing advice, though it never names a sibling 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?

Usage is implied rather than stated: the agent can infer it should be called when a wear recommendation is wanted, and it notes what is optional (intensity, preferences). There is no explicit when-to-use, when-not-to-use, or routing against the weather siblings, and the reference to 'the website's outfit card' points outside the toolset.

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