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

Annotations already mark the tool as read-only and non-destructive, and the description adds meaningful behavioral context: non-English queries violate the contract and their passages 'must be discarded, not answered from', article/annex numbers must be in English to match, and results are structured for browsing rather than answering. It also clarifies that after receiving passages, the assistant should answer in the user's language while quoting the law in English.

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?

The description is front-loaded with the all-caps language contract and clearly organized, but it is verbose for a single-parameter tool and repeats content already present in the input schema. It is readable and purposeful, yet not as concise as it could be.

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?

All necessary context is present: language constraints, valid query form, result structure, the handoff to `fetch`, and the explicit alternative tool for direct answers. Given the schema richness and annotations, nothing essential is missing for an agent to select and invoke this tool 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?

The schema description coverage is 100%, and the schema's `query` parameter already details the English-only requirement, legal register, act identifier handling, article/annex rewriting, and measured retrieval examples. The tool-level description largely repeats this guidance rather than adding new parameter-level semantics.

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 identifies the tool as a 'deep-research listing interface' over the same corpus as `search_eu_textile_regulations`, and specifies that it returns a browsable result list with `{results: [{id, title, text, url}]}`. It distinguishes itself from siblings by saying it is for listing results rather than producing a direct regulatory answer.

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?

It explicitly states when to use the tool — when a browsable result list is needed — and when not to: for a direct regulatory answer, use `search_eu_textile_regulations` instead. It also gives concrete handoff guidance, telling the agent to pass a result `id` to the `fetch` tool to read the full document.

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