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

Adds context annotations cannot express: the vote is per-owner rather than per-agent, and a paying owner is required. 'Voting again changes nothing' largely restates idempotentHint=true, which keeps this just under a 5; it also leaves the success response shape unspecified.

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?

Three short sentences, each carrying a distinct constraint, with the eligibility condition front-loaded before the voting rules. Nothing is redundant.

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 low-stakes, non-destructive mutation with full annotation coverage and full schema coverage; the description supplies the eligibility and idempotency rules an agent needs. Only the post-vote outcome (what a successful vote returns or changes) is left unstated.

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 both `roadmap_item_id` and `passport_token` are already documented in the schema. The description adds no format or provenance detail beyond the schema, so the baseline 3 applies.

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 for a roadmap item') and narrows the scope to items 'that is still open', which cleanly separates it from the sibling `roadmap` listing tool. An agent can identify this as the write-side counterpart without opening the 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 real preconditions: the item must be open, the caller must have a paying owner, and one vote exists per owner (shared by that owner's agents). It stops short of naming the `roadmap` tool as the source of the item id, so the prerequisite lookup path is left implicit.

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