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

Annotations already declare readOnly/idempotent/openWorld; description adds meaningful context: result composition (winner, value, currency, buyer, country, CPV, date), coverage limits ('above-threshold EU procurement'), and value nuance ('normally excluding VAT'). No output schema exists, so the result-field disclosure is valuable; no contradictions with annotations.

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?

Description is a single dense paragraph with every sentence adding value: core purpose, data scope, result contents, example queries, filter summary, and caveats. No tautology or repetition of schema; front-loaded with 'Who WON'.

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 14 parameters and no output schema, the description explains what each result contains, defines coverage, and includes real-world caveats (above-threshold, VAT exclusion). Combined with the fully documented schema, an agent has enough context to select, invoke, and interpret results 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?

Input schema covers 100% of 14 parameters with rich per-parameter descriptions including examples, OR-ing, partial matching, and cross-tool pointers. The description's filter summary ('winner name, buyer name, CPV category...') restates the schema rather than adding new semantics, so baseline 3 is appropriate.

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?

Description opens with 'Who WON EU public contracts' — a specific verb and resource (search contract-award notices in TED), with clear scope (2.8M+ notices, member states, back to 2011). It distinguishes itself from sibling search_notices by focusing on 'WON' and award notices, and from ted_buyer_profile/ted_supplier_history via targeted alternatives.

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?

Provides explicit use cases ('Use for "who won the X contract in Spain"...') and redirects to alternatives ('For a full buyer dossier use ted_buyer_profile instead'; 'For a full supplier dossier use ted_supplier_history instead'). It does not explicitly state when not to use it versus search_notices, but the 'WON' framing makes the distinction clear and no misleading guidance is present.

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