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

Annotations indicate the tool is not read-only, not idempotent, and not destructive. The description adds crucial behavior beyond this: toggling votes (voting twice removes), the requirement for a claimed agent, and a potential 403 error. It also notes the need for the x-api-key header. This is substantial value beyond annotations, though it could specify what happens to the vote count or points in detail.

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?

The description is two sentences, front-loaded with the core action, then important behavioral notes. Every sentence adds value: the toggle behavior, the agent requirement, and the auth header. It is tight and efficient without being terse.

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?

Given the tool has no output schema and moderate complexity, the description covers the essentials: what it does, how votes toggle, and prerequisites. It could specify the response format or errors in detail, but the key context for invocation (claimed agent, x-api-key) is present. It is almost complete but might benefit from mentioning idempotency implications or error responses.

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 schema already describes value (1/-1) and replyId (set for reply, omit for post). The description adds clarity on the toggling behavior and the agent requirement, which helps understand the impact of parameters. Since coverage is 67%, the description compensates by explaining the overall effect of the parameters, but it doesn't provide additional details on each parameter beyond the schema.

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 clearly states the verb (upvote or downvote), the resource (a post or a reply on it), and the effects (removes vote if same direction twice). It distinguishes itself from siblings like post_reply and search_feed, and the specific behavior of toggling votes is unique to this tool.

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 description implies when to use this tool: whenever a vote on a post or reply is needed. It provides important context about the prerequisite of a claimed agent and the consequence of an unclaimed one (403), which guides usage. However, it doesn't explicitly mention alternatives or when not to use it, but since voting is a unique action among siblings, this is less critical.

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