clips_launch

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

Annotations already declare non-destructive, idempotent, non-read-only, so the bar is lower; the description still adds real value by disclosing the transport side effect ('starts the transport unless start_transport is false') and the quantised launch timing. It does not say what happens when the target slot is empty.

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, no filler, with the core action stated first and the transport side effect immediately after. Every clause earns its place.

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 3-parameter tool with full schema coverage and no output schema, the description covers the action and its main side effect. It falls slightly short on failure behaviour (empty slot, invalid track) which an agent might need before committing.

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 each parameter already carries its own description, including the track UUID-vs-index tradeoff and the start_transport default. The description only echoes start_transport, adding nothing beyond the schema, so baseline 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?

A specific verb (Play) and resource (a session clip) with a scoping qualifier ('quantised like a click on its slot'). It is clearly distinguishable from clips_stop and from scenes_launch, but it never names those siblings to make the boundary explicit.

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 quantisation note, but there is no explicit guidance on when to choose this over scenes_launch (whole-scene) or transport_play, nor any mentioned prerequisites such as the track/slot needing an existing clip.

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