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

Adds substantial context beyond the readOnly/idempotent annotations: data provenance and freshness ('From public registers as of the last-checked date'), the per-licence source_url/last_checked_at verification path, result ordering, cursor pagination semantics, and strict argument handling ('Unknown arguments are rejected'). This is genuinely useful behavioral 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?

Purpose and filter set are front-loaded, and most sentences carry information. Minor waste: restating 'cursor is the next_cursor from a previous page' and the 'Unknown arguments are rejected' line, which the additionalProperties:false schema already enforces.

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 correctly compensates by describing the returned record shape (approved products with agent_access, LEI, licence summaries, certifications) and the ordering/pagination contract. Nothing an agent needs to call and interpret results 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 description coverage is 100%, so the schema already documents all 11 parameters, and the description largely restates them. The one added nuance — that licensed_in matches home or any passported country — is already present in the schema text, so it adds little. Baseline 3 is appropriate.

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 (Find) and resource (companies/fintech providers) and enumerates the exact filter dimensions (category, licence, licence type, authority, agent access). This clearly distinguishes it from siblings like search_organizations and search_products, which lack the licence/regulatory filter surface.

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?

Explicitly routes the agent to list_provider_filters for valid slugs and states the verification caveat ('Always confirm on the regulator's register'). However, it never says when to prefer this over search_organizations or search_products, so sibling selection is left partly to inference.

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