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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds that results may be incomplete ('available registration details and reviews'), which is useful context, but says nothing about what happens when the identifier isn't found or how the two identifier types behave differently.

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 short sentences, front-loaded with what is looked up and what comes back, with no filler or restatement of the tool name.

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 one-parameter, read-only lookup with no output schema, the description covers input modes and the shape of the response (registration details plus reviews). Only edge cases such as not-found behavior or identifier normalization are left unaddressed.

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 description coverage is 100% and there is a single required parameter, so the baseline is 3. The description confirms the same two identifier forms but adds no format detail (e.g. whether the company number needs zero padding, or what a valid slug looks like) beyond the 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?

States a specific verb ('check') and resource ('a UK home and interiors company') with two accepted identifier types, which separates it from entity-detail siblings like listing_detail or city_detail. It stops short of explicitly naming or contrasting the sibling tools it could be confused with.

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?

Usage is only implied: the description conveys that you supply either a Companies House number or a HouseJester page slug, which signals when this tool is applicable. There is no explicit 'use this instead of listing_detail when...' guidance or stated preconditions.

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