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

With no annotations, the description does useful work by disclosing cost ($0.25 USDC), the recency window (1-7 days), the result cap (up to 100), and the absence of director data. It says nothing about what fields come back, pagination, or whether any parameter combination is invalid, which matters for a tool with no output schema and no safety 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?

Dense and front-loaded: the primary use case leads, then limits, then pricing, then upsell paths. 'Upsell uk_leads' and the slash-path formatting are terse to the point of being cryptic, but no sentence 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 paid, unannotated, output-schema-less data tool, the description covers cost, scope, caps, and alternatives — the main things an agent needs to choose it. It leaves the return shape undefined beyond 'no directors', so the agent cannot tell what a lead record contains before spending $0.25.

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 0%, so the description must compensate — and it broadly does, implicitly mapping all five params: sic, location, postcode_area, days ('1-7 days'), and limit ('up to 100 cos'). Formats (SIC code shape, postcode_area granularity, minimum values) remain unstated.

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 and scope: cheap UK new-incorporation lead lists filterable by SIC/location/postcode_area, with the coverage limit (up to 100 cos) and an explicit exclusion (no directors). That distinguishes it well from uk_leads and uk_leads_feed, though the name 'lite' does little work on its own.

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?

'Use this for cheap ...' plus explicit price-differentiated pointers to uk_leads ($1) and /uk-leads-feed ($25) tells the agent when to step up to a richer or recurring alternative. It stops short of saying when this tool should NOT be used, and the sibling names in prose are paths rather than tool names.

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