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

Annotations declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds only the word 'recorded', implying retrieval of pre-existing data, but does not describe return format, error behavior (e.g., missing weather), authentication needs, or rate limits. It adds minimal value beyond annotations.

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?

The description is a single, concise sentence with no wasted words. However, it is under-specified and not front-loaded with a clear action, which limits its usefulness. Conciseness is fine, but the structure prioritizes brevity over necessary detail.

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 simple read tool with one parameter and full schema coverage, the description is too minimal. It does not explain what weather data is returned (e.g., temperature, conditions) or what happens if no weather is recorded, and there is no output schema to fill that gap. It fails to differentiate from siblings that may also return activity weather.

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%, with the single activityId parameter documented as 'Numeric id'. The description does not add any meaning beyond what the schema already provides. Baseline 3 is appropriate when the schema fully documents the parameter.

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 identifies the resource (weather for an activity) but lacks a specific action verb like 'get' or 'retrieve'. It is a noun phrase that roughly restates the tool name, leaving the exact operation somewhat implied rather than stated. It does not distinguish from siblings like get_activity_details, which may also include weather.

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?

There is no guidance on when to use this tool versus alternatives. No prerequisites, no conditions, no mention of related tools. The description offers no context for selecting this tool over others.

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