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

With no annotations, the description does useful work: it discloses the data source (Contracts Finder), that results are live/open, and critically that output is capped at 3 newest results, which prevents an agent from expecting a complete listing. It omits rate limits, auth requirements, and what happens when nothing matches.

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?

A single front-loaded sentence with no filler; the 'FREE' marker and the result cap are both placed early. The telegraphic dash construction is slightly terse but nothing is wasted.

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?

For a two-parameter read-only search with full schema coverage and no output schema, the description covers source, matching inputs, and the size of the returned set. Only the behavior on zero matches and region value validation remain unstated, which is minor.

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%, so both parameters are already documented with examples. The description adds only that region is optional and that matching is keyword-based, which is the baseline expected when the schema does the heavy lifting.

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 the resource precisely (live open UK public-sector tenders from Contracts Finder) and the result scope (top 3 newest, matched by keywords and optional region). It implicitly signals it is the truncated variant of tender_match_full via 'top 3 newest', but never names that sibling, so differentiation requires inference.

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?

'FREE' hints at a cost tradeoff, but the description never states when to prefer this over tender_match_full, closing_soon, or new_since, nor any exclusions or prerequisites. The agent must infer usage from the sibling names alone.

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