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

Annotations already cover safety (readOnly, idempotent, non-destructive, openWorld), so the bar is lower. The description adds genuinely useful behavioral context the annotations lack: the x402 pay-per-call model and the free daily allowance, which affects how an agent should budget repeated calls.

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?

Two dense sentences: the first front-loads the resource and searchable facets, the second handles only the pricing caveat. No filler, no repetition of the title.

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 values need not be explained, and all seven params are optional and schema-documented. The description covers facets and cost; it omits only minor operational details like result pagination or ordering behavior, which keeps it just short of full completeness.

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 all seven parameters with their formats and enum-like values. The description restates the same facets (status values, type, dates, min value) without adding syntax or semantics beyond the schema, 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?

States a specific resource (Contracts Finder notices) and enumerates the filterable facets: keyword, status, type, publication date, and minimum value. An agent understands exactly what corpus is searched, though it never explicitly contrasts itself with siblings like uk-tenders__notice or uk-tenders__find-a-tender-latest.

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?

The description never says when to pick this tool over uk-tenders__notice, uk-tenders__find-a-tender-latest, or the EU equivalents, nor when-not to use it. The only usage-adjacent content is pricing (free allowance, then $0.003/call), which is cost guidance rather than selection guidance.

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