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

Annotations already establish that this is a read-only, idempotent, non-open-world lookup. The description adds useful behavioral context about the returned data itself: it is sourced, includes source URLs and check dates, documented limits and approvals, legal entity and licence status in Spain, and availability by market. It does not cover error behavior or auth, but for a read-only lookup the added sourcing and content detail is substantive.

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 a single, front-loaded sentence that efficiently lists the entry's contents. The long parenthetical field list is dense but every item conveys what the agent will receive, and there is no filler or repetition.

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?

Because there is no output schema, the description appropriately carries the burden of explaining what the tool returns, and it does so extensively. It is nearly complete for a read-only full-record lookup, with the main remaining gap being explicit routing guidance versus sibling tools rather than return-value explanation.

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 description does not mention either parameter. The schema describes 'id' well with examples, but the other parameter, 'lang', has only an enum and default with no explanation, and the description does nothing to clarify whether it controls response language or filtering. With 50% schema description coverage and no compensating parameter detail in the description, this is a clear gap.

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 resource: the 'Full AgentBroker Index entry for one provider', and enumerates the entry's contents. It is specific enough to distinguish a full single-provider lookup from list/compare/search siblings, though it does not explicitly name those siblings or state that this is the detailed-record retrieval tool.

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 phrase 'for one provider' implies usage when the agent already has a provider identifier and needs the complete record. However, there is no explicit guidance on when to use this instead of search_providers, compare_providers, or list_changes, and no stated exclusions or prerequisites.

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