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

The readOnlyHint annotation already establishes that this is a safe read operation, and the description's 'Search' action is consistent. However, the description adds no additional behavioral context (e.g., result limits, matching behavior, or required authorities) beyond the annotation, so it meets the baseline but does not go further.

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?

The description is a single sentence that directly states the tool's core function. Every word earns its place, and it is front-loaded with the verb and resource. It is appropriately concise for a simple search tool.

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?

With a single parameter, a read-only annotation, and an output schema present, the description is adequate for a basic search tool. However, it lacks any mention of limitations, regional scope, or differentiation from sibling tools, making it incomplete for agents choosing among many similar search tools in the larger context.

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?

The schema has no description coverage for the 'name' parameter. The description only says 'by name,' which maps the parameter to a company name but does not specify exact vs. fuzzy matching, required format, or whether it is the registered name or trading name. This minimal compensation is insufficient given the 0% schema coverage.

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 clearly states the action ('Search'), resource ('Companies House'), and object ('company by name'). However, it does not distinguish between this tool and the sibling dd_company_search, which likely performs a similar search, so it misses the sibling differentiation required for a 5.

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 description provides no guidance on when to use this tool versus alternatives such as dd_company_search, dd_company_profile, or other Company House tools. It does not mention exclusions, alternatives, or specific contexts, leaving the agent to infer usage from the name alone.

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