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

Annotations already cover read-only, idempotent, non-destructive behavior. The description adds valuable context beyond the annotations by revealing the return format ('not wrapped in `value`') and the $expand capability, which are not otherwise specified. No contradiction exists.

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 concise sentences cover purpose, return format, and expansion capability without redundancy. Each sentence contributes distinct information and the description is front-loaded with the core action.

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 simple fetch-by-id tool with comprehensive annotations and schema, the description is complete. It explains the key behavioral quirk (direct return) and optional expansion, and no output schema exists, so further return details are unnecessary. It also gives a concrete entity example to reduce ambiguity.

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?

The input schema provides a full description for all four parameters (id, entity, expand, select) with high coverage. The description only mentions $expand in passing, adding no new semantic details beyond the schema. Baseline 3 is appropriate since the schema does the heavy lifting.

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 clearly states the action: 'Fetch a single Folketinget entity record by its numeric id' with a concrete example (Sag(1)). This distinguishes it from sibling tools like query_entity by highlighting the id-based lookup and direct return format.

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 usage context is implied by 'by its numeric id'—use when you have a specific numeric id and need a single record. However, it does not explicitly name alternatives or exclusion criteria, such as recommending search tools for non-id-based queries, so guidance is present but not fully developed.

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