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

Annotations already convey idempotency and non-destructiveness, and the description adds the important behavioral constraint 'Only with the user's confirmation,' which is not present in the annotations. It also clarifies that 'clear' removes a prior vote, adding state-change semantics beyond the raw enum.

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?

Two sentences, both load-bearing: the first states the operation and allowed values, the second states the required human-confirmation condition. No filler or redundant restatement of schema fields.

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 five-parameter mutation tool with no output schema, the description covers the essential operational semantics: what vote values mean, the source of place_id, and the user-confirmation requirement. It could be slightly more complete by noting the participant token/auth requirement, but the schema descriptions already handle that.

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 80%, so the baseline is 3, but the description adds real meaning by mapping 'up', 'down', and 'clear' to concrete actions (up-vote, down-vote, remove vote) and by sourcing place_id from get_plan. This goes beyond the schema's bare enum list.

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 opens with a concrete verb-resource pair: 'Up-vote, down-vote or remove your vote on a place.' It enumerates the exact vote modes and identifies the source of place_id (get_plan), making the tool unmistakable among siblings like add_place or set_rsvp.

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?

It gives clear context: this tool is for voting on a place after retrieving candidates via get_plan, and it adds the critical precondition 'Only with the user's confirmation.' It does not explicitly name alternatives or exclusions, so it misses the top tier.

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