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

Annotations provide only readOnlyHint and openWorldHint, but the description goes far beyond. It discloses partial coverage (~30% of notices attached in a deferred pass), the stock start point (stock.depuis), the pending-attachment counter (stock.avis_en_attente_de_rattachement), the bounded 'aucune_annonce' response, and privacy exclusions (no personal data). It also reveals the payment mechanism (x402 or api_key). None of this contradicts annotations; it enriches them.

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 dense paragraph, but it is arranged logically: purpose first, then source and notice types, then coverage caveats, then payment. Every sentence carries substantive information (coverage, payment, exclusions). It is longer than ideal, but given the complexity (3 params, partial data, payment), the length is justified and there is no fluff.

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?

For a tool with an output schema and 3 parameters, the description is remarkably complete: it specifies the data returned (notice code, type, regime, date, link), coverage limitations and how to interpret them, payment options, and the sibling for the complementary data. An agent has everything needed to call it correctly, including edge cases like pending attachment and bounded answers.

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% — every parameter (api_key, x_payment, company_number) already has a clear description in the schema. The tool description adds little parameter-specific meaning beyond what the schema provides; it mentions payment indirectly but the schema already explains the api_key and x_payment details. Baseline 3 applies since the description does not materially exceed the schema.

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 states a specific verb and resource: 'Corporate insolvency notices of a UK company from The Gazette', and enumerates the exact notice types (winding-up resolutions, petitions, liquidators, administrators, etc.). It also distinguishes itself from the sibling get_uk_company_insolvency by noting it covers procedural notices rather than current status. This makes the purpose unmistakable.

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?

Usage guidance is explicit: 'The procedural journal Companies House does not give (use get_uk_company_insolvency for the current status)'. This names the alternative tool and the condition for choosing it. It also clarifies coverage limitations and when a bounded answer (aucune_annonce: true) is appropriate, leaving no ambiguity about when to invoke this tool.

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