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

Annotations already declare destructiveHint=true and idempotent=false, and the description usefully adds that `overwrite` replaces this agent's not-yet-started says (the destructive surface) and that `append` queues behind earlier says. It also discloses the live-room paraphrase behavior and the `verbatim: false` outcome, which annotations cannot express.

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?

One dense paragraph, front-loaded with the core action before the mode semantics. Every clause carries information, though the parenthetical live-room aside is slightly heavy for a single sentence.

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, return values need not be described (though it mentions ok/seq) and annotations carry the safety profile. The description still supplies the mode-queue semantics and live-room nuance an agent needs, leaving only permission/prerequisite details unstated.

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 67%: `text` and `session` are documented in the schema, but the `mode` enum values are not. The description compensates by defining each enum value's exact effect, which is real added meaning beyond the structured data.

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 states a specific verb and resource ('The voicebot speaks `text` aloud in the call') and immediately clarifies its scope (verbatim in normal mode, rephrased in a live room). It is clearly distinguishable from siblings like `show`, `decide`, and `next`, though it never explicitly names those alternatives.

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 description thoroughly explains the *mode* parameter values (append/overwrite/revise), which is effective parameter-level guidance. However, it gives no explicit guidance on when to use `say` versus sibling tools such as `show`, `send_data`, or `decide`, so tool-selection context is only implied.

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