Log an activity

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

With no annotations, the description carries the transparency burden and does disclose key behavior: the output is an image card, metrics are mapped gamification-style, and honesty is required. It implies persistence through 'your own history' but does not explicitly state that an activity record is saved.

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?

Three sentences, front-loaded with the tool's purpose and output, followed by the trigger condition. The playful wording earns its place by reinforcing the Strava-style behavior without adding fluff.

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?

The output is described as an image card, schema documentation covers parameters, and trigger conditions are clear. It could be more complete by explicitly stating that the activity is persisted and what happens on return, but none of this is critical for selecting or invoking the tool.

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?

The schema description coverage is 100%, so the schema already documents all 17 parameters. The description adds a helpful metaphor—line churn becomes distance, errors become elevation—but does not explain individual parameter details, which is acceptable given full schema coverage.

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 action and result: finish a coding session and receive a Strava-style achievement card as an image. It distinguishes itself by promising the card, badges, and personal records, though it does not explicitly contrast with sibling tools.

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?

Gives clear call triggers: when the user asks to brag or at the end of a session worth remembering. It does not list excluded scenarios or alternative sibling tools, but the guidance is sufficiently clear for an agent to know when to invoke it.

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