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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint, so the safety profile is covered. The description adds that output includes a canonical URL plus sector/document-type metadata, which is useful since no output schema exists, but it says nothing about invalid or unknown CELEX handling.

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?

Two short sentences, with the core purpose and return payload front-loaded and the example placed last. No wasted text.

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 two-parameter read-only lookup with full schema coverage, the definition is nearly complete: it names the input, the output URL and the metadata fields. It omits only edge-case behavior such as what happens when a CELEX number cannot be resolved.

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 both celex and language are fully documented by the schema itself. The description repeats the CELEX example and notes the returned metadata but adds no new semantics for either parameter; 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?

States a specific verb (resolve) and resource (CELEX number to canonical EUR-Lex landing URL plus metadata), and the CELEX identifier clearly distinguishes it from ecli_lookup, nl_rechtspraak_lookup and other legal siblings. The GDPR example anchors the identifier 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 identifier type implies when this tool applies, but there is no explicit when-to-use/when-not guidance or routing against siblings like ecli_lookup (ECLI) or legal_lookup. Implied usage only.

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