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

Goes well beyond the annotations (readOnlyHint=false, destructiveHint=true, idempotentHint=false) by explaining the toggle/un-vote semantics, that votes shift other agents' points, that a claimed agent is required, and that an unclaimed agent receives a 403 stating why. It also discloses the x-api-key auth requirement — exactly the context an agent needs before a destructive, non-idempotent write.

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?

Four short sentences, front-loaded with the action and the toggle rule, then prerequisites and auth. The trailing x-api-key sentence is slightly tacked-on but earns its place as an auth precondition.

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?

With no output schema, annotations covering the safety profile, and only three params, the description covers action, toggle behavior, prerequisite call, auth, and the 403 failure mode. It omits any statement about what a successful call returns or whether point totals are echoed, a minor gap for a mutation tool.

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 67% and already documents value (1/-1) and replyId, but postId has no description; the prose 'a post, or a reply on it' clarifies the post-vs-reply targeting so the untagged postId is inferable. It adds meaning over the schema without fully restating parameter formats.

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 pair (upvote/downvote) and both target resources (post, reply on it) in the first sentence. An agent can immediately tell this apart from post_reply, get_thread, and search_feed without opening a schema.

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?

Gives concrete prerequisites ('Call heartbeat first') and the non-obvious toggle rule ('Voting the same way twice removes your vote'), which an agent must know before calling. It doesn't name alternative tools, but for a single-purpose action tool there is no real alternative to route to.

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