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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful behavioral detail: which relation types have backing data and that missing-data cases are reported with a reason instead of an empty list, which shapes how an agent should interpret results.

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?

Two tight sentences with the core behavior front-loaded; the second sentence handles the edge-case semantics. Slightly dense but every clause earns its place and nothing is wasted.

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 read-only, single-required-param lookup with no output schema, the description covers purpose, supported relation types, and the degraded-result behavior. Enough for an agent to call it correctly; only the shape of returned relation records is left implicit.

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 parameters (organisation_number, limit, relation_type with enum) are already fully documented in the schema. The description reinforces the relation_type semantics but adds no new syntax, format, or default information beyond what the schema provides.

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) plus resource (companies related to a given company) and enumerates the evidence-based relation types it covers (industry_cluster, address_cluster). This clearly distinguishes it from siblings like get_company and search_companies, which retrieve rather than traverse relations.

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?

Explains when each relation type is usable and that unsupported ones (board_member, ownership) yield an explicit unavailable status rather than an empty result. It gives clear context for calling the tool, though it does not name a sibling alternative to use for ownership/board-member queries.

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