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

With no annotations, the description carries the full burden and does so well: it discloses pricing ($0.5 USDC per call via x402 in _meta['x402/payment']), a free 3-row preview escape hatch, and provenance ('every block names its source and date') plus a note that matching, country union and summaries are computed by Lilambd. It does not cover failure modes, rate limits, or response shape, which keeps it below a 5.

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?

It is front-loaded with the core question, then the source breakdown, then the route map and the payment note, so an agent can stop reading at any depth. The five-ledger enumeration is long but every clause names a distinct data family, and the only near-redundancy is the route list overlapping the schema.

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 three-parameter aggregation tool with no output schema and no annotations, the definition supplies sources, provenance, payment model, preview option, and route-to-input mapping. The remaining gap is what a response actually looks like structurally and how large it can get, which matters given the five-way join.

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 coverage is already 100%, so the baseline would be 3, but the description goes further by mapping each route value to its expected inputs (name/lei/wikidata for /answer, q*/limit/offset for /brands, q/limit/offset for /search), which the schema's flat enum-like string does not convey. It also explains that sample=true yields exactly 3 rows for free.

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 resource ('one company brief') and enumerates exactly what it is joined from: GLEIF group ownership, Open Food Facts brand owners, OpenAlex research organisations, tender notices, and cross-border ownership links. That is far beyond a restatement of the name, though it never explicitly distinguishes itself from plausible siblings such as 'orgs' or 'place-brief'.

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 'Routes:' line functions as operational guidance, telling the agent that /answer is for name/lei/wikidata inputs while /brands and /search are query-driven, and the exclusion 'Organisations only, no data about individual people' rules out a whole class of use. What is missing is any comparison to sibling tools that also cover organisations, so the agent must infer when this is preferable.

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