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

The description discloses the authentication method (REST, token in metadata) but does not clarify whether the tool itself performs registration or merely returns instructions. There are no annotations to contradict, but side effects, network calls, or state changes are not mentioned.

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 concise, consisting of two clear sentences. The first sentence states the primary purpose, and the second sentence provides authentication guidance, with no redundant or filler content.

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?

The description gives enough context to understand the tool's role and how to use the token, but it is ambiguous whether the tool outputs the requirements or performs the registration. It does not describe the output format or what the user should do with the requirements, which leaves some gaps given there is no output schema.

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 tool has zero parameters, and the schema coverage is trivially 100%. The description does not need to explain any parameters, but it also adds no parameter-related semantics beyond the token passing instruction, which is relevant to MCP metadata rather than tool parameters.

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 the tool provides 'free business customer registration requirements for paid lookups,' which clearly indicates its purpose is related to registration requirements. It is distinguishable from sibling tools like get_data_freshness and get_ofgem_price_cap, though the phrase could be more explicit about the tool returning a list of requirements.

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 explains that registration uses REST and that the resulting token should be passed as customer-token in MCP request metadata, giving practical usage guidance. However, it does not explicitly say when to use this tool over the siblings, such as 'use this before paid lookups' or 'use this to obtain access requirements.'

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