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

Goes well beyond the readOnlyHint/openWorldHint annotations by disclosing the paid-call model ($0.002 USDC via x402 on Base/Solana/Arc), the fact that failed calls are free, and the limited scope to published notices. Pricing and billing-failure semantics are exactly the kind of operational context annotations cannot carry.

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?

Three tight sentences: identity and filters first, then returned fields, then cost model. Nothing redundant, and the most decision-relevant facts are front-loaded.

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 an output schema present, the brief return-field summary is sufficient and the description still covers scope, jurisdiction and payment behavior. An agent has everything needed to decide and call 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 coverage is 100%, with defaults and formats already documented for days, limit and country. The description restates the ISO 3-letter code and the 1-90 day window but adds no new syntax or edge-case guidance, so the baseline 3 applies.

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?

Names a specific source (TED / Tenders Electronic Daily) and resource (EU public procurement notices) with explicit filters. Easily separable from sibling gov tender tools such as gov_anac_italy_procurement or gov_uk_gov_tenders by jurisdiction and source.

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?

States the filter model (buyer country ISO code, publication date window 1-90 days) and a scope limitation ('published notices only'), which tells the agent what this search will and will not surface. It stops short of explicitly naming alternative siblings for non-EU or pre-award data, so no full routing guidance.

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