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

Annotations already cover read-only, idempotent, closed-world and non-destructive, so the bar is lower; the description still adds real behavior: truncation of long provisions with metadata.complete=false and a next_cursor that only get_provision can continue. It is silent on auth/rate limits and on the meaning of '(compatible)' in the title, keeping it short of a 5.

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-loaded with 'Use this to...', then scope, truncation behavior and routing in four tight sentences with no filler. Every sentence adds a fact the schema or annotations do not carry.

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 one-parameter read tool with full annotations and an output schema, the description covers entry criteria, id constraints, truncation and alternatives. The only unexplained element is why this tool is labeled '(compatible)' relative to get_provision, which leaves the fetch-vs-get_provision choice slightly underspecified.

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 single id parameter has 100% schema coverage with rich detail, so the baseline is 3. The description adds a meaningful constraint beyond the schema — ids must be minted by this service, and free-text citations are rejected — but otherwise repeats the cite-anchor example already present in the schema.

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: 'open and cite an EU legislative provision', limited to 'simple retrieval of one provision's text by its cite anchor id'. It also distinguishes itself from both get_provision ('returns more') and resolve_citation ('free-text citations belong to resolve_citation'), so an agent can separate it from siblings without opening schemas.

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 an explicit entry condition ('a provision found by search'), an explicit exclusion ('accepts only ids this service minted — free-text citations belong to resolve_citation'), and points to get_provision when paging, applicability or typed warnings are needed. Routing is inferable without guessing.

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