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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely non-structured behavior: a per-call charge of $0.004 USDC settled via x402, which materially affects an agent's decision to invoke it. It stops short of covering pagination or how the paid PDF links are delivered.

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 plus a short pricing clause; the resource is front-loaded and the parenthetical enumerations are informative rather than filler. Slightly dense but nothing that wastes the reader's time.

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, no-output-schema tool the description covers content well and flags cost, but it leaves the identifier question ambiguous (name vs number), says nothing about result limits or pagination, and gives no hint that this is a paid call until the final clause. Adequate but with clear gaps against a 4-parameter surface.

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 only 50%: `number` and `category` are documented in the schema while `name` and `limit` are bare. The description's 'Filter by category' merely echoes the category field's own enum and adds no syntax or format detail, leaving the two undocumented parameters unexplained and uncompensated.

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 specific resource (UK company filing history) and enumerates its contents (accounts, confirmation statements, officer changes, secured charges, insolvency cases), so an agent knows exactly what comes back. It does not, however, distinguish itself from close siblings like uk_company, uk_officer, or uk_companies_search.

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 only guidance offered is 'Filter by category', which is about invocation mechanics rather than tool selection. There is no statement of when to use this instead of uk_company, uk_officer, uk_disqualified, or uk_kyb, nor any mention of which company identifier to supply.

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