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

Adds substantial context beyond the annotations: the vote is publicly visible to the post's readers, the call returns updated counts, it executes without a confirmation prompt, and it is reversible with one call. These details clarify impact and reversibility in a way the raw annotations (destructiveHint, openWorldHint) cannot.

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?

Five short sentences, each carrying distinct information: action scope, mechanics, return value, visibility, and confirmation/reversibility. Front-loaded with the primary action and no filler.

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 three-parameter mutation with no output schema, the description covers what the tool does, how the option parameter behaves in different states, what is returned (counts), the social visibility of the action, and the reversibility/confirmation profile. Nothing material is missing for an agent to call it correctly.

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 100%, so baseline is 3, but the description goes further by explaining the special semantics of option 0 (retract) and what happens when a new option is supplied to an existing vote (the vote moves). This adds meaningful behavioral meaning to the option parameter beyond the schema's 'Answer number' description.

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+resource ("Vote in a post's poll") and immediately covers the full range of actions: vote, change vote, retract. This clearly distinguishes it from read-only siblings like get_poll_results or get_post.

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?

Provides clear conditions for each mode: voting anew, moving an existing vote, and retracting via option 0. It implies that viewing counts without voting is a separate operation (get_poll_results exists as a sibling), but does not name that alternative explicitly, which keeps it just below a 5.

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