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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is for extra context — and the description delivers: it discloses truncation behavior (metadata.complete false, metadata.next_cursor), that continuation happens via get_provision, and that only service-minted ids are accepted. That is rich disclosure beyond structured fields.

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 front-loaded sentences that each carry routing or behavioral information, with no filler. Slightly dense and the id-example overlaps the schema, but nothing is wasted.

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?

Output schema exists, so return values needn't be explained, yet the description still covers the truncation case and its continuation path. For a single-parameter read tool with full annotation coverage, nothing an agent needs is missing.

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 examples like "psd-2 Art 97" are already documented. The description still adds a constraint the schema lacks — only ids this service minted are valid, and version qualifiers retain their edition — which meaningfully narrows what the agent should pass.

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 (open/cite) and resource (one EU legislative provision) and distinguishes itself from siblings by name — free-text citations belong to resolve_citation, and get_provision is the richer alternative. An agent can route between fetch, get_provision, and resolve_citation without opening a schema.

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?

Explicit routing: use this for provisions 'found by search'; free-text citations go to resolve_citation; get_provision is named for when more is needed (paging, applicability, typed warnings). When-not conditions are stated, not implied.

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