stop_playback

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

There are no annotations, so the description carries the full burden of behavioral disclosure. It only states the action itself without revealing potential side effects, such as whether the playhead resets, whether recording also stops, or whether it errors if already stopped. The description adds no context beyond the tool's name.

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 that directly states the tool's function. It contains no filler or redundant details, earning a perfect score for conciseness and structure.

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 simplicity (0 params, no annotations), the description is sufficient for an agent to understand and invoke it. The presence of an output schema means return values do not need explanation. However, it lacks context about whether any preconditions exist (e.g., transport must be playing), which keeps it from being a 5.

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 tool has zero parameters, and the input schema is empty with 100% coverage. Per rubric, the baseline is 4 when there are no parameters. The description adds no parameter information because none is needed.

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 'Stop the session transport' clearly identifies the action (stop) and the specific resource (session transport). It differentiates from sibling tools like start_playback, stop_clip, and fire_clip by targeting the global transport rather than individual clips or scenes.

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 gives no explicit guidance on when to use this tool versus alternatives. It does not mention that this stops playback globally, nor does it contrast with stop_clip or pause-like behaviors. The usage is only implied by the name and description, providing no exclusions or alternatives.

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