voice_speak

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

With no annotations, the description carries the full burden. It usefully discloses the core side effect (audio is spoken directly into the user's ears, so the text is heard not returned), but says nothing about auth/config prerequisites, latency/blocking behavior, or what happens if no TTS provider is configured.

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?

Front-loaded with the action and the when-to-use rule, followed by a compact Args block. The Args section partly echoes schema titles but earns its place by adding examples and the provider list.

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?

An output schema exists so return values need not be explained, and the description covers purpose, timing, formatting constraints, and every parameter. The only real gap is failure/configuration behavior for a tool whose whole job is an external side effect.

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%, so the description must compensate, and it does: it labels all four parameters and supplies concrete example values for message, provider (full list of accepted providers), model, and voice. It notably enumerates provider names that the schema does not constrain via an enum.

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 ('Speak a short, natural voice summary') plus scoping constraints (1-2 sentences, to the user's ears). An agent immediately understands this produces audio output rather than text, which distinguishes it from the read-only voice_status sibling by name and role.

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?

Explicitly says when to use it ('at the end of substantive turns to tell the user what was done') and gives a clear exclusion ('without reading code, diffs, or markdown formatting'). It does not mention voice_stop or voice_status as alternatives or when to avoid speaking, so the routing picture is incomplete.

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