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

With no annotations at all, the description carries the full load and does disclose meaningful behavior: 30-day term, daily cadence, webhook delivery, director enrichment, deduplication, and a concrete price of $25.00/30d USDC. It omits what happens at term expiry (renewal, lapse) and how payment is collected, which keeps it short of a 5.

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 dense sentence, front-loaded with the 'use this for' cue, with the filtering criteria, enrichment traits, and cost packed efficiently. Nothing is redundant and the price sits at the end where it does not obstruct the primary action.

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 four-parameter, no-output-schema, no-annotation subscription tool, the description covers purpose, delivery mechanism, filters, data quality traits, and cost. Gaps remain around payload contents, webhook endpoint requirements, and post-term behavior, but the core call decision is well supported.

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 does partially by naming sic, location, and postcode_area as the matching criteria and framing webhook as the delivery target. It gives no formats or examples (e.g. whether postcode_area expects 'SW' vs 'SW1A'), does not say the filters are combined with AND, and does not clarify that only webhook is required.

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?

The description states a concrete verb and resource: a recurring daily push of newly incorporated UK companies, filtered by SIC/location/postcode_area, enriched with director data and deduplicated. That is far more specific than the bare name, though it never names siblings like uk_leads or uk_leads_lite to make the distinction explicit.

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...' signals intended usage and the mention of a webhook implies an ongoing subscription rather than a one-off query, which is real context. However, there is no guidance on when to pick this over uk_leads/uk_leads_lite, or on prerequisites (a publicly reachable endpoint, payment of the stated fee).

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