playback_start

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 describes the action and parameters but lacks details on permissions, rate limits, error conditions, or what 'Response data' contains. It doesn't contradict annotations.

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?

Well-structured with a clear purpose statement followed by parameter and return sections. Slightly verbose in listing all parameter details, but each sentence adds necessary information without redundancy.

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 tool with no annotations, no output schema, and complex parameters, the description covers purpose and parameters well but lacks behavioral context (e.g., side effects, error handling) and details on the return value beyond 'Response data', leaving gaps for agent usage.

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 description coverage is 0% with only one undocumented parameter ('request'), but the description compensates by detailing six specific parameters (call_control_id, audio_url, loop, overlay, stop, target_legs) with meanings, requirements, valid values, and defaults, adding significant value beyond the schema.

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 clearly states the specific action ('Start audio playback') and resource ('on a call'), distinguishing it from sibling tools like 'playback_stop', 'speak', or 'make_call' which involve different audio/call operations.

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 implies usage for playing audio during calls but doesn't explicitly state when to use this versus alternatives like 'speak' (for text-to-speech) or 'playback_stop'. No exclusions or prerequisites are mentioned.

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