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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=false and openWorldHint=true; the description adds the non-obvious auth requirement, which is real value beyond the structured fields. It leaves unstated what happens to a prior vote on re-vote, which is the main behavioral gap.

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 short sentences, front-loaded with the action and the possible values; the auth note is appended compactly. No filler, though slightly telegraphic.

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?

A mutation tool with no output schema and a sparse schema; the description covers the action and auth but omits what the post reference should look like and what a successful vote returns or whether it can be undone, leaving an agent to infer call mechanics.

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 only 33%: only 'token' is documented in the schema. The description covers the 'vote' enum values, which is already visible in the schema, and 'Needs sign-in' loosely explains the optional token, but the required 'post' identifier is unexplained in both places.

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 (Mark) and resource (a commons post) plus the exact three accepted dispositions, which matches the enum in the schema. No sibling tool overlaps this action, so an agent can route to it unambiguously.

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?

'Needs sign-in' gives one prerequisite and implicitly points at sign_in/sign_in_status, but there is no explicit when-to-use versus when-not, and no guidance on switching or retracting a vote.

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