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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered; the description goes further by disclosing real data limitations — group-level breakdown exists only for a small subset of votes, missing sources are named rather than silently dropped, and every statement carries evidence with a Kennung, evidence page and original link. That is substantive behavioral context an agent could not get from annotations. It stops short of describing response size or latency for multi-source aggregation.

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 core purpose is front-loaded in the first clause and the source list follows logically; nothing is padded with filler. It is a dense single paragraph that mixes purpose, caveats, citation instructions and a no-AI disclaimer, which could be broken up for scanability, but each sentence carries information.

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?

With no output schema, the description carries the burden of explaining returns, and it does: a per-statement evidence trail with identifier plus two links, and explicit notice of coverage gaps. For a one-parameter aggregation tool this is nearly complete, missing only a hint about result volume or how partial-source results are ordered.

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% and the single parameter description already contains the same two example formats ('2023/0448(COD)' or '2023-0448') that appear in the tool description, so the description adds no meaning beyond the schema. 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?

The description states a concrete verb and resource: it assembles, for a given EU dossier, who supports and who opposes, by aggregating named source types (roll-call votes with tallies and group breakdown, EESC/CoR opinions, rapporteur lobby meetings, adopted text). This is clearly distinguishable from siblings such as get_eu_vorgang or compare_eu_groups, which do not claim to build a for/against matrix across multiple evidence sources.

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?

The use case is clear: an agent knows to call this when it needs an aggregated position picture for one procedure rather than a single document lookup. What is missing is explicit routing guidance — no sibling (e.g. compare_eu_groups, get_eu_vorgang, get_mep_vote) is named as the alternative for a narrower question, so the agent must infer when this aggregation is overkill.

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