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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description still adds real value: the 60-second minimum / ~2-minute recommendation, the 'never read a text' rule, the content of topics (text repeats them one per line) and that voice_messages may be one note or several assembled together. It does not say whether the guide content is static across calls, which is the remaining gap.

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 purpose before any recording rules, and most clauses carry distinct information. It is a long sentence-chain and the trailing 'Arguments: {}' is pure filler, but it is not padded in substance.

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?

There is no output schema, so the description carries the burden of describing return values — and it does, field by field. Combined with the usage rule and the recording constraints, an agent has everything needed to decide when to call it and how to present the result.

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 arguments, so the baseline is 4; the trailing 'Arguments: {}' merely restates the empty schema. Nothing else is needed here and nothing misleading is added.

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?

Specific verb ('Get') plus a well-scoped resource ('free-speech guide for a new voice reference'), and it enumerates exactly what comes back (instructions, tips, topics, voice_messages, accepted_formats). The line 'Existing voices and recorded dialogue are separate' tells an agent that this is not the tool for inspecting or reusing already-recorded material.

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?

Explicit timing guidance ('Show it proactively before the user starts recording') plus an explicit prohibition ('never use it as the video's dialogue'), which is the key misuse to avoid given the sibling generate/video tools. The only minor gap is that no sibling is named as the alternative for existing voices.

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