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

Beyond the readOnlyHint/openWorldHint annotations, the description discloses a hard result cap of 10 and, unusually, the commercial model — $0.20 per call settled in USDC on Base via x402 — which materially affects whether an agent should invoke it. It does not cover rate limits, pagination, or what happens with zero results.

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 tight sentences with zero filler, front-loading the result shape and follow-up usage before the cost caveat. Every clause carries information an agent needs.

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 read-only, filter-driven lead-gen tool with no output schema, the description usefully states the returned fields and the result ceiling. However, it never explains filter interactions or defaults (e.g. what mode/locality do when omitted), leaving gaps an agent must guess at before calling.

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?

With 0% schema description coverage, the description has to carry parameter meaning and only partly does: 'Up to 10' clarifies the max cap and 'overdue (or soon-due)' hints at the mode enum. Industry, locality, and dueWithinDays — including their defaults — are left entirely to the bare schema.

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 names a concrete resource — UK companies with overdue or soon-due Companies House accounts — and the payload it carries (director and email details), which separates it from sibling feeds like companies_new or companies_changes_feed. It omits an explicit verb, but the retrieval intent is unambiguous.

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?

'Leads for accountants' implies the intended audience and use case, but there is no explicit when-to-use framing, no named alternatives among the sibling company tools, and no statement about when this is inappropriate. Usage is inferred rather than stated.

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