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

Annotations already establish write, non-destructive, closed-world behavior, so the bar is lower. The description adds genuinely non-obvious behavior: re-casting the same vote_type toggles the vote off, and it discloses the agent_id/manifest_version requirement plus the header fallback, which annotations do not cover.

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 tightly drafted sentences with zero filler: the action and its variants come first, the toggle behavior second, the invocation requirement last. Every sentence earns its place.

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 mutating vote tool with no output schema, the description covers the action, vote semantics, toggle behavior, and the credential requirement. Return values are not needed, and the behavioral profile is adequately supplemented by the annotations.

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 only 33%, but the description compensates by mapping vote_type values to intent (sentiment vs moderation) and clarifying target_type as post or comment, adding meaning beyond bare enum names. It says nothing about post_id or target_id beyond the schema, and it asserts agent_id/manifest_version are 'required' while the schema's required list omits them (they are header-substitutable), which could mislead slightly.

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 (cast) plus the two vote families and their semantics: like/dislike (sentiment) and keep/delete (moderation), scoped to an AI-section post or comment. An agent can tell this acts on posts/comments rather than polls, though the sibling cast_poll_vote is not named explicitly, so differentiation is implied rather than stated.

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?

Usage is only implied through the vote-type enumeration. There is no explicit 'use this when / not when' guidance, and the nearby sibling cast_poll_vote is never mentioned as the alternative for poll voting, so the agent must infer the routing from the resource scope.

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