Stop

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

The description explicitly notes idempotency, matching the annotation, and clearly indicates the action of stopping playback. Annotations also provide non-destructive and non-read-only hints, but the description adds direct behavioral context.

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 short sentences—'Stop playback. Idempotent.'—convey the essential information without any superfluous text.

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?

Given the tool's extreme simplicity (no parameters, output schema exists), the minimal description is fully adequate. The output schema handles return value documentation per the scoring rules.

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?

There are no parameters to document, and the schema coverage is 100%. The description does not need to add parameter information since none exist.

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 clearly states 'Stop playback', specifying the exact verb and resource. It distinguishes from sibling tools like fl_play, fl_toggle_play, and fl_record by focusing on the stop action.

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 provides no guidance on when to use this tool versus alternatives such as fl_toggle_play or fl_record, and lacks context for prerequisites or exclusions.

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