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

Beyond annotations (readOnlyHint, idempotentHint, destructiveHint false), the description adds the deduplication rule, exclusion of tenders, precomputed nightly refreshes, instant responses, and the exact output fields. This provides rich, non-obvious behavioral context.

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?

Every sentence earns its place. The description is front-loaded with the core purpose, then covers definitions, answer framing, compute model, and routing to the sibling tool, all in only three concise lines.

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?

With all parameters documented, an output schema present, annotations already covering the read-only/idempotent safety profile, and the description covering output fields, semantics, and alternatives, nothing the agent needs to select and invoke this tool correctly is missing.

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% and the only parameter (year) is clearly documented as a 4-digit year, with omit for all-time in the schema. The description merely reinforces this by saying 'optionally for one year.' Baseline 3 is appropriate since the schema already carries the parameter meaning.

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 opens with a precise verb-resource statement: committed public procurement value by CPV category (2-digit division), and it names the exact answer it provides: top divisions by spend. It differentiates itself from search_tenders by explicitly stating that tenders are excluded and that search_tenders should be used for other divisions.

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?

It gives an explicit use case ('answers what does the Greek state spend the most on') and directly names the alternative path: 'Use search_tenders with cpv= for divisions outside the top list.' This is clear when-to-use and when-not-to-use guidance in the context of the sibling tools.

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