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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description doesn't need to restate safety. It adds useful behavioral details: mention of 'contains matching' for text searches and 'opaque cursor pagination,' which go beyond the schema. However, it does not disclose performance characteristics, rate limits, or what the response contains beyond the mention of fields like buyer, deadline, and CPV. Given annotations cover the core safety profile, a 3 is appropriate.

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 with zero fluff. It front-loads the purpose and key attributes, then adds the matching behavior and pagination note, and finally the routing to open_calls. Every sentence earns its place, making it highly concise and well-structured.

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?

Given the tool's moderate complexity (6 params, all documented in schema, no output schema), the description covers the essential behavioral aspects: matching semantics, pagination, and scope (companies/authorities). It also provides a clear alternative for non-tender opportunities. It does not explain how to use the cursor in practice (e.g., that next_cursor appears in the response), but that is implied and the schema covers the cursor parameter. Overall, it is complete enough for an agent to invoke correctly.

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 schema already documents all parameters thoroughly. The description adds value by specifying that title/buyer text uses contains matching and that cursor is opaque, which clarifies parameter semantics beyond the schema's simple field names. It also clarifies that the 'cpv' parameter is a CPV code prefix, which is not fully explicit in the schema's 'CPV code prefix' description. This goes beyond the baseline of 3.

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 identifies the tool as fetching public procurement notices and lists key attributes (buyer, deadline, CPV). It clearly distinguishes it from the sibling open_calls by noting that open_calls is for grants and funding calls, not tenders. However, it does not fully describe the exact scope (e.g., country-specific public procurement), which is a minor gap.

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 explicitly directs users to use open_calls for grants and funding calls instead of tenders, which provides clear when-not-to-use guidance and differentiates from a key sibling. It also hints at the tool's scope by saying 'Companies and authorities only,' but does not explicitly say when to use this tool versus other siblings like search_companies or get_company. The guidance is useful but lacks a broader decision tree.

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