playback_start

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

No annotations are provided, so the description carries the burden. It explains some behavioral options (loop, overlay, stop, target_legs) but does not disclose prerequisites (e.g., call must be active), side effects, or failure modes. It adds moderate context beyond the schema but lacks depth.

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 docstring is well-organized with Args and Returns sections, using concise bullet-like lines. No redundant text, though the Returns line is generic and could be more informative. Overall, it is clear and efficient.

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?

While the description explains all parameters, there is a critical mismatch: the schema expects a single 'request' object, but the description lists individual arguments. This relationship is not clarified. Additionally, no output schema, annotations, or usage guidance means the description is not fully self-contained for an agent to invoke correctly.

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 input schema only defines a 'request' object with additionalProperties, so schema coverage is 0%. The description fully compensates by listing each parameter, its required/optional status, valid values, and defaults. This is the sole source of parameter semantics.

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 action ('Start audio playback') and the resource ('on a call'), which is specific and distinct from siblings like playback_stop and speak. The parameter list further clarifies the operation.

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 context is implied (when you need to play audio on a call), but there is no explicit guidance about when to use this tool versus alternatives like speak or playback_stop. No when-not-to-use scenarios or exclusions are mentioned.

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