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

Annotations already cover read-only and open-world traits, and the description adds genuinely non-obvious behavior: the per-call price ($0.002 USDC via x402 on Base/Solana/Arc), the fact that failed calls are not charged, and the hard limit that only the newest page is returned. That is real context beyond structured fields, though nothing is said about auth or rate limits.

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 source and returned fields, then the scope constraint, then cost. Two sentences, minimal waste; the parenthetical OCDS/stage hint is dense but earns its place for an agent matching data sources.

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?

An output schema exists so return formatting needn't be explained, and the description covers source, scope and paid-call economics. The remaining gap is disambiguation from the similarly named UK tenders sibling, which matters given this toolset's density.

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 sole parameter (limit, 1-10, default 5) is fully documented in the schema. The description adds no syntax or default detail beyond that, so 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?

States a specific verb+resource (UK awarded public contracts from Contracts Finder, OCDS stage=award) and enumerates the returned fields (notice ID, date, buyer, title, supplier, award value in GBP). Clear on its own, but it never distinguishes itself from the near-identically named sibling gov_uk_gov_tenders, which an agent could easily pick by mistake.

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?

'Award notices only; the newest page of results' implicitly tells the agent what this cannot do (open/pending opportunities, historical pages), which is useful scoping. However, no alternative tool is named and there is no explicit when-to-use framing beyond that constraint.

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