peppol_directory_search

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

With no annotations, the description carries the behavioral burden and does disclose that the search is public, unauthenticated, unrelated to SMP lookup, and requires at least one search filter. It does not cover pagination/rate-limit details, but the output schema covers return structure.

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 two sentences, front-loads the core action, and every clause adds useful context: scope, authentication, relationship to SMP, and input requirements. 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 an 8-parameter search tool with a full output schema and 100% schema coverage, the description supplies the missing preconditions and scoping: public access, directory-resource, no SMP relation, and the minimum filter requirement. An agent can call the tool correctly without further inference.

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 100%, so description adds value mainly by declaring that at least one of q, participant, name, country, doctype must be supplied, which is not visible in the schema's required array. That is a meaningful invariant beyond the parameter descriptions.

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: 'Search the Peppol Directory for registered participants.' It also distinguishes itself from related operations by explicitly saying this is not SMP lookup, which separates it from siblings like peppol_lookup_participant.

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 identifies public, unauthenticated use and gives an explicit 'no relation to SMP lookup' exclusion, but does not name the alternative tools to use for SMP lookup. It also specifies the minimum filter condition, which is practical guidance.

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