stop

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

With no annotations, the description carries the behavioral disclosure burden. It goes beyond the name by clearly describing two effects: playback stops and the playhead returns to start. It does not cover edge cases like already-stopped state, but the core behavior is unambiguous.

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?

One sentence with no filler, and the primary action is front-loaded before the secondary effect. Every word contributes meaning.

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 parameterless transport-control command, the description is functionally complete: it tells the agent what it does and what state change it causes. Return values are not described, but no output schema exists and the command's semantics are simple enough that nothing essential is missing.

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 100% schema description coverage, so there is nothing for the description to clarify about inputs. The baseline for parameterless tools is 4, and no deduction is warranted.

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 verb and resource: 'Stop playback', and adds the distinguishing behavior 'return playhead to start position'. This clearly differentiates it from sibling tools like pause, which would pause without resetting the playhead.

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 playhead-reset detail implicitly indicates when this tool should be used instead of pause, but no explicit when/when-not guidance or alternative tool comparisons are provided. Usage context is inferable rather than stated.

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