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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, so the safety profile is covered. The description adds only the 'only when the user asks' caveat — mildly useful, but it does not disclose what happens when the voice is not currently favorited or any auth context. No contradiction with annotations.

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?

A single front-loaded sentence with the verb and resource first and the usage caveat second; no filler. It is appropriately sized for a one-parameter tool.

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 low-complexity, single-parameter mutation tool whose annotations carry destructive/idempotent semantics and whose schema documents the token, the description is reasonably complete. The main omission is behavior on a non-favorited voice, which the idempotentHint annotation effectively covers.

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?

With one parameter at 100% schema description coverage, the schema fully documents the 'voice' token and even points to list_favorite_voices for obtaining it. The description adds no parameter meaning beyond that, which is the expected baseline.

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 (remove) and resource (a voice from the user's favorites), which is clearly distinguishable from the inverse sibling add_favorite_voice. It stops short of explicitly naming the counterpart tool, so it is clear but not sibling-routing.

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 parenthetical '(only when the user asks)' implies a usage condition but gives no explicit when/when-not rationale tied to alternatives such as add_favorite_voice or list_favorite_voices. Usage is implied rather than stated.

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