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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description reinforces read-only with "Not for changing the words" but adds no behavioral caveats beyond that (no auth, rate-limit, or side-effect notes), and the enumerated return fields overlap the existing output schema.

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?

Three short sentences, front-loaded with the trigger condition and ending with a crisp exclusion. The enumeration of returned fields is slightly redundant against the output schema but remains compact and readable.

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?

For a simple single-parameter read tool with an output schema, the description covers purpose, trigger, and exclusion adequately and need not explain return values. It is complete enough to invoke correctly, though a pointer to update_speech for edits would tighten it.

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 100% with a single well-documented speechId parameter, so the baseline is 3. The description adds no format or constraint detail about the id beyond what the schema already provides.

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?

"Read a voiceover line" plus the description's concrete scope (full wording, translation, or audio link of ONE line) states a specific verb and resource. It clearly distinguishes this from get_project/get_video/get_tutorial siblings by naming the exact entity it returns.

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?

"Use this when someone needs the full wording or translation of one voiceover line, or its audio link" gives a clear triggering condition, and "Not for changing the words" provides an explicit exclusion that steers the agent away from update_speech. It stops short of naming the alternative tool directly, so a 4 rather than a 5.

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