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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds non-trivial context beyond that: it reveals the shape of the response (id, gender, accent, a default marker) and the workflow coupling to ringkit_update_business. It does not mention whether the list is static/catalog-wide or business-specific, which is the one remaining behavioral ambiguity.

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?

Two short sentences, no filler, and the workflow position is front-loaded before the details. Every clause carries information: what is listed, what fields come back, and which tool consumes the choice.

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 no input parameters and no output schema, the description carries the return-value burden itself and does so by naming the fields returned including the default. What is missing is minor: how the default is surfaced (flag vs. first entry) and whether the set is global or business-scoped.

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 zero parameters, so there is no parameter semantics to explain; the baseline applies. The description correctly implies no inputs are needed to retrieve the catalog.

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 ('List the receptionist voices') and enumerates the returned fields (id, gender, accent, default), so the agent knows exactly what comes back. It does not explicitly distinguish itself from the closest sibling, ringkit_get_voice_stack, which also concerns voices.

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?

Places the call in a sequence ('Step 3: Pick a voice') and names the follow-up action explicitly ('Pick one with ringkit_update_business {voice}'), which gives the agent a clear when-to-use and what-to-do-next path. It stops short of stating exclusions or contrasting with ringkit_get_voice_stack / ringkit_put_voice_stack.

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