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

Goes well beyond the annotations (which already mark it read-only, idempotent, open-world, non-destructive) by disclosing a daily rate limit and the graceful degradation path when the limit is hit (answer points to the free web lookup). It also tells the agent that returned data includes certificate validity, which signals freshness-sensitive metadata rather than a live transaction.

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?

Front-loaded with the core action and the identifier argument, followed by short, purposeful sentences on scope, rate limits, and the optional hint. The opening sentence is dense with a nested parenthetical and a colon-list, but nothing is filler.

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 two-parameter lookup with an output schema already present, the description covers everything an agent needs: what input to supply, what comes back at a conceptual level, the read-only metadata scope, and the rate-limit failure mode. No significant gap remains.

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 0%, so the description carries the burden and mostly does: it explains the identifier with concrete examples (Belgian company number, Peppol ID 0208:0521875440) and defines country as an optional two-letter hint. It stops short of giving explicit format constraints or noting that country may disambiguate identifier collisions.

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 concrete verb and resource: find the access-point provider that receives a given business identifier's e-invoices on the Peppol network. It also enumerates the returned fields (provider organisation, SMP host, document types, certificate validity) and scopes the tool with 'Provider metadata only', which separates it from sibling tools like providers/provider that presumably list or manage provider records.

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?

Clearly frames the trigger condition: you have a business identifier (company number or Peppol ID) and want to know which access point receives its invoices. The 'Provider metadata only' clause functions as a scope exclusion, and the rate-limit sentence tells the agent what happens at the boundary, but no sibling tool is named as an alternative for related questions (e.g. provider catalogue browsing).

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