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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely non-obvious data semantics beyond that: a null company_count means the corpus pass has not run, not a measured zero, which prevents a serious misinterpretation.

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 sentences, front-loaded with what the tool returns, then filters, then the null-value caveat. Every sentence carries information an agent would otherwise get wrong; there is no filler.

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?

With no output schema, the description does carry the return-shape burden and partly meets it (joined to countries/regions/industries, company_count semantics). It still does not describe the per-result fields or pagination behavior, leaving a modest gap.

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 the baseline is 3. The description goes beyond the schema on scope by restating horizontal as regimes binding a provider with NO industry tag, and confirms the kind/jurisdiction filters, but says nothing about q, page, limit, or context.

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 gives a specific verb and resource ("Browse the laws, statutes and accreditations the catalog tracks") and clarifies the joined shape (countries, regions, industries). It does not name a sibling to contrast with, so the agent must infer that get_regulation is the singular fetch and find_rules/find_scopes are separate catalogs.

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 gives a concrete when-to-use case with rationale: use scope=horizontal for regimes that reach a provider with no industry tag, "the question tags alone cannot answer." It also names the kind and jurisdiction filters, but offers no explicit exclusions or pointer to an alternative tool for related needs.

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