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

Annotations already declare readOnlyHint=true, openWorldHint=false, and idempotentHint=true, indicating it's a safe, read-only, closed-world operation. The description adds value by stating that every fact appears on the public website, which addresses data provenance and reliability. There's no contradiction.

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 (three sentences) and front-loaded with the essential purpose. The final instruction 'Call this first' is a clear directive, though it could be seen as slightly redundant with the usage guidelines.

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 zero-parameter, read-only tool with rich annotations (readOnly, closed-world, idempotent), the description fully covers what an agent needs: the tool's purpose, the specific data it returns, and that it's the first call. No output schema is needed because the description lists the content.

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 parameters, and schema coverage is 100% (by default since there are no params). The description provides no parameter-specific info, but since there are zero params, the baseline is 4, and the description adequately explains what the tool returns without needing to detail 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 clearly states the resource (Referral Flooring) and enumerates the specific facts it provides (phone number, opening hours, towns served, etc.). It distinguishes itself from siblings by being the 'published facts' tool, though it doesn't explicitly name which sibling it differs from.

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 clear context: call this first for any question about the business facts. It implies this is the go-to for business information, but doesn't explicitly say when NOT to use it or which sibling to use instead for other types of queries.

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