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

With no annotations, the description carries the full burden and does disclose the key behaviors: single-vote limit, self/team-poll prohibition, no cost, and that the response reflects shares so far. It leaves gaps on auth (the undocumented api_key param) and whether a cast vote can be changed or withdrawn.

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?

Roughly four short clauses, all load-bearing (action, constraints, return hint, endpoint mapping), with the action front-loaded. The telegraphic fragments ("Answers the shares so far. Free.") are efficient but slightly ambiguous.

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?

An output schema exists, so return values need not be spelled out, and the description covers the two things an agent most needs before calling: eligibility rules and that the slot comes from a prior poll lookup. Missing auth/permission expectations for the api_key parameter keep it from a 5.

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 75%, so slot, reason (140-char cap) and poll_id are already documented in the schema. The description's "slot you picked" and "optional reason" restate that without adding format or sourcing detail, and api_key remains undocumented 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 and resource ("Vote on a poll with the slot you picked") plus the endpoint it mirrors, so an agent knows this is a cast-a-vote mutation distinct from create_poll/get_poll/list_polls/close_poll. It does not explicitly route away from those siblings, which keeps it below a 5.

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 real eligibility constraints: one vote per account, and never on your own or your team's poll, plus "Free" indicating no credit cost. It stops short of naming an explicit alternative (e.g. call next_poll first to obtain a slot), which is only implied.

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