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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), but the description adds critical behavioral context they cannot: coverage is genuinely partial, below-threshold notices routinely omit supplier and value, and the response exposes won_count vs value_disclosed_count plus data_as_of so the gap is not misread as 'no data'.

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 purpose before caveats, and every sentence carries information. The shouted 'COVERAGE IS GENUINELY PARTIAL' and the long em-dash clause are slightly heavier than needed but functional.

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 no output schema, the description must carry return semantics, and it largely does: the buyer-side view, award dates, disclosed EUR values, won_count vs value_disclosed_count, and data_as_of. It does not describe pagination or how sample_limit affects the response, a minor remaining gap.

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 date format, partial-match supplier, and the sample_limit default/max (10/25). The description's example company names are already in the schema, so it adds little parameter-level meaning beyond the default baseline.

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?

Specific verb+resource: 'Contract-win history for a GERMAN supplier/contractor ... across German OCDS tender notices', with the exact output (buyers, award dates, EUR values). The supplier-centric framing also distinguishes it from the mirror sibling germany_buyer_spend_history without needing to open either schema.

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?

Clear context for when it applies: the user must have a German supplier/contractor name, and it covers German OCDS notices only. No explicit exclusions or named alternatives (e.g. germany_search_tenders, germany_buyer_spend_history) are given, so it stops short of a 5.

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