list_audio_sources

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

No annotations exist, so the description carries the full behavioral burden, and it does not explicitly say this is a read-only enumeration with no side effects. However, with zero parameters and an output schema, the description is not required to explain return values, and a listing operation is low-risk enough that the gap is small.

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?

It is a single short sentence with no padding, but it is a grammatical fragment with a dangling parenthetical ('Apps currently using audio (to choose the source), and the default microphone and output'), which reads ambiguously rather than being front-loaded with a clear verb.

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?

With an output schema present and zero parameters, the definition covers the essentials of what the call returns, so an agent can invoke it. It still omits that the call is read-only and does not state explicitly that it should precede start_recording to select a source.

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 no parameters, so there is nothing for the description to disambiguate; baseline 4 applies. The description correctly implies the call is argument-free.

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 is a noun phrase enumerating what is returned (apps using audio, default microphone, default output) rather than stating 'List audio sources', though the intent is inferable. It does distinguish itself from the recording siblings by being device/source discovery, but the phrasing is fragmentary enough that an agent must read the tool name to confirm the verb.

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 parenthetical '(to choose the source)' implies the tool is meant to be called when the agent needs to pick a capture device, likely ahead of start_recording. That is an implied workflow hint rather than an explicit when-to-use/when-not statement, and no alternative tool is named.

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