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

Annotations already mark the tool as read-only and non-destructive; the description adds value by explicitly listing what the tool does not do: fetch, scan, persist, or verify AI inclusion. This goes beyond the annotations and helps prevent incorrect assumptions about side effects.

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 tightly written sentences with no filler. The main action is front-loaded, and the crucial limitations are listed compactly in the second sentence.

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 pure scoring tool with a rich schema, output schema, and annotations, the description covers all necessary selection and invocation context. The negative scope prevents misuse, and the schema handles parameter details.

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%, so the schema already documents all three parameters clearly. The description adds only the general notion of 'caller-supplied signals', which maps to the schema but does not enrich parameter meaning beyond it. Baseline 3 is appropriate.

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?

Description uses a specific verb ('Score') and resource ('caller-supplied website and business discovery signals'), and clearly distinguishes this from likely siblings by stating it does not fetch the website, run an AI scan, or verify AI inclusion. The negative scope makes the tool's unique role immediately clear.

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 phrase 'caller-supplied signals' gives clear context for when this tool is appropriate, and the negative list implies when to look elsewhere (e.g., when website fetching or AI scanning is needed). It does not explicitly name sibling tools or give direct 'use this instead' guidance, so it falls just short of a 5.

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