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

The annotations already cover safety traits (readOnlyHint, idempotentHint, non-destructive, closed-world), so the description's added value is in the result shape: totals, group/country splits, dossier linkage, and optional individual MEP votes. It does not discuss pagination or error behavior, but it adds useful behavioral context beyond the annotations.

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?

The description is front-loaded with the core usage condition and remains compact at two sentences. Both sentences carry useful information: the first defines the tool's purpose and return scope, and the second explains parameter usage and provenance.

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 read-only lookup tool with full schema coverage and annotations covering safety, the description supplies the missing return-value context and explains the optional members parameter. No output schema exists, but the description sufficiently describes what the agent will receive.

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 the schema already documents both parameters, but the description adds meaningful context by explaining where vote_id can come from and by giving examples of valid members values such as "EPP", "S&D", "DE", and "FRA".

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?

The description uses a specific verb and resource: retrieving one European Parliament roll-call vote. It also enumerates the returned content (totals, political-group and country splits, dossier, optional individual MEP votes), which makes the tool clearly distinguishable from list-style siblings such as list_votes.

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?

It gives an explicit trigger: "Use this when you need the result of one European Parliament roll-call vote." It also names valid sources for the vote id (list_votes, get_dossier, get_mep, or an epvotes.com URL), though it does not explicitly state when not to use this tool versus those siblings.

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