Play audio on a live call

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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true. The description supplements this by explaining that `mix: false` replaces the conversation audio, which gives the destructive hint concrete meaning, and by constraining inputs to https .mp3/.wav. However, it omits consequences like the max-5-files limit and what happens to audio already playing.

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?

A single front-loaded sentence covers purpose, file constraints, the endpoint, and the key parameter default, followed by one short clause naming the stop tool. No sentence is wasted.

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 6-param, no-output-schema action tool with safety annotations already present, the description supplies the essential call behavior (live call, mix semantics, stop tool). Minor gaps remain around loop/length behavior and the 5-file cap, but nothing critical to invoking it correctly is missing.

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 already 83%, so the baseline is 3, but the description adds real value: it clarifies mix's semantics (overlay vs. replace) beyond the schema's terse 'Mix with the call audio', and adds the https/.mp3/.wav format constraint and ordering behavior not stated in the `urls` schema entry. legs, loop, and length are left to the schema alone.

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 (play) and resource (audio files) with scope ('into a LIVE call'), which clearly separates it from speak_text and play_audio_to_conference_member. It also cites the underlying endpoint (POST /Call/{uuid}/Play/), removing ambiguity. It stops short of explicitly naming the sibling tools it is not.

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?

Gives the operating context ('LIVE call') and routes the agent to the terminating tool by naming stop_audio, which is the natural follow-up. It does not state when this tool is preferred over speak_text or play_audio_to_conference_member, so no explicit exclusion guidance is present.

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