play

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

No annotations are provided, so the description carries the full burden. It does disclose the meaningful behavioral fact that playback targets the *active* sequence, but it says nothing about whether the call blocks, what happens if no sequence is active, or whether playback continues asynchronously.

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?

A single front-loaded clause with zero filler. It is efficient, though the brevity edges toward under-specification rather than polished 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?

For a simple one-optional-param transport tool with full schema coverage and no output schema, the description is close to sufficient. It falls short only on the prerequisite (active sequence) and the asynchronous/blocking nature of playback, which an agent would benefit from knowing.

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 coverage is 100% and the single optional 'speed' parameter is fully documented in the schema (including reverse and multiplier semantics). The description adds nothing beyond that, so the baseline of 3 applies.

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 target: 'Start playback of the active sequence', which distinguishes it from transport siblings like stop, step_forward, and set_playhead. It does not explicitly name an alternative, but the action itself is unambiguous.

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?

Usage is implied by the verb and the 'active sequence' scoping, but there is no explicit guidance on when to prefer play over step_forward/step_backward, no prerequisite stating an active sequence must be set, and no mention of how to stop.

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