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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld). Beyond that, the description adds real behavioral context: the register includes past as well as current officers, entries carry varied officer_role values with is_board_director=false for secretaries, and each officer carries ECCTA verification status and cross-company appointments. It stops short of noting pagination or volume limits for large registers.

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 most valuable insight, that the list is not all directors, arrives in the second sentence and is front-loaded. The closing field inventory (appointment date, resignation date, nationality, occupation, birth month/year, ECCTA status, other companies) is slightly long-winded but each item earns its place by describing the return payload.

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 carries the full burden of explaining return values, and it does so thoroughly: per-officer fields, the officer_role enumeration, the is_board_director flag, and nested other-company appointments. The reporting caution ('never describe the whole list as directors') closes the main correctness gap for an agent summarizing results.

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 single parameter is fully documented in the schema (100% coverage) with a pattern and a concrete example ('00445790' for Tesco PLC). The description adds no syntax or format detail for company_number, so this is the expected baseline where the schema carries the load.

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 ('Get the current and past officers for a UK company') and immediately clarifies the scope mismatch with the tool name, explaining it is the full officer register rather than just directors. An agent can distinguish this from get_psc or get_company 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 implies when to reach for it ('full picture of an officer's corporate history in one call'), which hints at using this instead of repeated lookups, but it never names a sibling alternative or states an exclusion. Usage is inferable from the described scope rather than explicitly guided.

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