transport_play

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses the unconditional nature, the non-stopping behavior, and the internal composition ('checking transport_get_play_position first and only toggling if not already playing'). This is more than most descriptions provide, though it could also mention whether playback is synchronous or whether it can fail on empty projects.

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 dense paragraph, slightly longer than necessary, but every clause earns its place: the unconditional behavior, the contrast with the toggle sibling, the lack of a dedicated 'always play' action in v4, and the composition logic. It is front-loaded with the key behavior before the parenthetical explanation.

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 zero parameters and an output-schema-less tool, the description covers the essential context: what triggers playback, how it avoids the toggle problem, and how it relates to the sibling. It lacks a note on failure modes (e.g., no audio loaded) but that is a minor omission for a transport action.

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, so there's nothing to document. The description adds context about the action's semantics ('current cursor position','unconditionally'). A baseline of 4 is appropriate for no-parameter tools since there is no schema burden to compensate for.

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 states a specific verb ('Start playback'), a specific resource ('current cursor position'), and an explicit scope ('unconditionally... never stops playback'). It clearly distinguishes itself from the sibling transport_play_stop, which is the most similar tool in the sibling list.

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 explicitly says when to use this tool versus the alternative: it names transport_play_stop, explains that the alternative is a toggle, and states the condition ('if not already playing'). It also explains the composition logic (checking transport_get_play_position first), which gives the agent a clear decision rule.

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