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

Goes well beyond the readOnly/idempotent annotations: it discloses that missing end dates do not imply current membership, that a missing detail returns success with found=false, and how snapshot_changed invalidates pagination state. These are non-obvious semantics an agent could not infer from the schema.

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?

Front-loads purpose and section behavior, then pagination, then failure/discovery semantics — a sensible order with no filler. Some sentences are very compressed (e.g. 'Missing detail succeeds with found false'), which slightly taxes parsing without wasting space.

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 an output schema present, return shapes need not be explained, and the description still covers the operationally risky parts: mode selection, pagination continuation and invalidation, and the found=false failure mode. An agent has everything needed to call this 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 would be 3, but the description adds real meaning: the section switch between overview and memberships, and the coupling of snapshot to offset (required above 0, restart at 0 without snapshot after snapshot_changed). It does not restate limit/language syntax, which the schema already handles.

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 (read MEP identity or membership history) and enumerates exactly what is covered: committee, delegation, and political-group records. It also distinguishes itself from the sibling lookup tool by pointing to euparl_search_meps for ID discovery.

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?

Clearly routes between the two modes (default overview for identity/count, memberships for the paged history) and names euparl_search_meps as the way to obtain an ID. It lacks an explicit 'when not to use this' clause, but the alternatives and conditions are stated.

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