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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds behavioral context about the output (includes prices and explanatory page) and the filtering behavior via the query parameter, which is beyond the annotations. However, it does not disclose other traits like pagination, sorting, or rate limits, though the tool is simple and the output schema exists.

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 exactly two sentences. The first sentence states the core function and scope, front-loading the purpose. The second sentence provides usage context and parameter guidance. There is no filler, redundancy, or unnecessary detail—every sentence earns its place.

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 tool with a single optional parameter, an output schema, and annotations covering safety, the description is complete. It tells the agent exactly what the tool does, when to use it, and how to narrow results. The output schema covers return structure, so no further explanation is needed.

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 input schema has 100% coverage for the single optional 'query' parameter, with a description that includes examples ('reviews', 'ads', 'website'). The description's 'Pass a query to narrow the list' essentially restates the schema's filtering purpose without adding new meaning. Since schema coverage is high, the description adds minimal value, but it does confirm the intended usage.

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 a specific verb ('List') and resource ('what Build My Digital builds and runs for UK local businesses, with the published price for each service and the page that explains it'). It clearly differentiates from siblings by focusing on service/pricing listing rather than page retrieval (get_page) or website scanning (scan_website). The scope (UK local businesses) and purpose are 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?

The description gives explicit when-to-use guidance: 'Use when someone in the UK asks who can build a website, get them found on Google or AI search, or run their social, email, ads, reviews or AI agents, and wants real prices without a sales call.' It also mentions the parameter usage ('Pass a query to narrow the list'). However, it does not explicitly mention when not to use it or name alternatives, but the context is clear enough that an agent can route correctly.

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