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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive behavior. The description adds valuable context: it internally probes each entity with ai_visibility_check, ranks results, and returns a ranked list with specific metrics (score, confidence, signal density). This goes beyond what annotations provide.

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 two sentences plus an example and a return-value sentence. It front-loads the main action ('Compare AI visibility...'). The structure is clear but could be slightly more concise by integrating the example more efficiently.

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?

Given no output schema, the description adequately describes the return format (ranked list with score, confidence, signal density). It mentions the internal call to ai_visibility_check and the competitive audit context. Missing details like entity count limits (2-8) are in the schema, and error handling is not discussed. Annotations cover safety. Overall, reasonably complete for a read-only comparison tool.

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 coverage is 100%, so baseline is 3. The description adds marginal value: it notes the first entity is treated as the 'subject' for narrative and clarifies 'context' is applied to every probe. However, these details are minor; most parameter meaning is already in the schema.

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 specifies the verb 'compare' and the resource 'AI visibility across multiple entities'. It differentiates from sibling 'ai_visibility_check' by emphasizing multi-entity side-by-side comparison and ranking. An example use case ('does Claude know about us as well as our competitors?') further clarifies purpose.

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 states the tool is 'useful for competitive AI-marketing audits', providing clear context. However, it does not explicitly state when not to use it (e.g., for single entity checks, where ai_visibility_check would suffice) or list specific alternatives. Implicit differentiation from sibling tools is present but not explicit.

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