transport_play

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

The annotations already declare idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds the concrete no-op condition ('does nothing if already playing'), which is genuinely useful context beyond the generic idempotency flag. It omits whether playback resumes from the current playhead position versus restarting the scene/looped region.

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 with zero filler, and the primary action is front-loaded before the conditional no-op clause. Nothing could be trimmed without losing information.

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 zero-parameter, no-output-schema transport control, the description covers the action, the starting position, and the already-playing edge case. The one remaining gap is how this relates to arrangement_play and whether playback resumes stopped state at the playhead or restarts from the last start point.

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 takes zero parameters, so there is no parameter semantics to document and the baseline of 4 applies. Nothing in the schema is left unexplained.

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 ('Start playback') and adds the scope detail 'from the playhead,' which separates it from transport_seek and transport_stop. It does not explicitly distinguish itself from arrangement_play, which is the only real ambiguity among siblings.

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 strongly implied by the name and by its pairing with transport_stop, but no explicit when-to-use or alternative-selection guidance is given. It does not say how it differs from arrangement_play, which also appears to start playback.

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