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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is known. The description still adds real value by enumerating what the tool will NOT do (no fetch, no scan, no persistence, no verification), which is behavioral context beyond the structured hints.

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 sentences, zero filler, purpose front-loaded and the boundary condition immediately after. Every clause 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?

An output schema exists, so return values need not be explained, and annotations cover the safety profile. The description adequately frames scope and input origin for a 3-param, stateless scoring tool, though a hint about how to interpret an overall score would round it out.

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% and each nested field is documented in the schema, so the description carries no additional burden. The phrase 'caller-supplied website and business discovery signals' loosely maps to websiteUrl/signals but adds no syntax or format detail. 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?

States a specific verb and resource ('Score caller-supplied website and business discovery signals'), which is clear and distinct from building an action plan or summarizing scan evidence. It does not name its siblings explicitly, so differentiation is inferred rather than stated.

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 negative list ('does not fetch the website, run an AI scan, persist data, or verify inclusion') effectively tells the caller when this tool applies: only when signals are already in hand. This routes away from scan/fetch tools but stops short of explicitly naming the alternatives.

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