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

With no annotations, the description carries the full burden, and it delivers: it discloses the return shape of each hit (url, title, text-as-of date, offset, snippet) and a role-based access constraint. It does not state read-only guarantees, result limits, or rate behavior, but for a search tool that is a minor gap against otherwise solid disclosure.

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?

Well front-loaded with the action and corpus, and 'Not a web search' is placed prominently as a disambiguator. The dense single block of em-dash-separated clauses is informative but slightly heavy; each sentence still earns its place.

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?

There is no output schema, so the description's enumeration of the hit fields is genuinely useful and offsets that gap. Combined with the permission note and source list, an agent has enough to call the tool correctly; only edge behavior (limits, empty results) is unaddressed.

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 parameters are already documented in the schema (query with an example, limit with a max and default). The phrase 'by words and by meaning' hints at the query's hybrid keyword/semantic nature, but the description adds no format or syntax detail beyond the schema. 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 and resource ('Search the laws, regulations and standards'), names the actual corpus (EUR-Lex, legislation.gov.uk, Fedlex, FATF), and explicitly distinguishes itself from web search. An agent can tell it apart from the sibling list_legal_library and search_wiki without opening any 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?

The description gives clear context for use: it operates only on laws already ingested from official sites and, crucially, clarifies 'Not a web search.' The permission caveat ('Open where the company lets an agent role read laws') explains when access applies. It stops short of explicitly routing to alternatives such as list_legal_library, so it is strong but not exhaustive.

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