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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description does not contradict them. It adds behavioral detail beyond the annotations by specifying that results include names, descriptions, and full input schemas with curated examples, and that each result is 'ready to call directly, no second schema lookup needed.' This is useful, non-obvious context.

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 well-structured and efficient: it starts with the core action, lists representative domains, explains the return format, and closes with practical guidance. Each sentence contributes unique value, and the length is appropriate for the tool's discovery purpose.

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 its read-only nature, the lack of an output schema, and the richness of the domain list, the description is nearly complete. It explains what is returned and how results are ready for direct invocation. It could mention error behavior or edge cases, but that is a minor gap for a discovery 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 description coverage is 100%, so the baseline of 3 applies. The description does not add parameter-level semantics beyond what the schema already provides; however, it does mention the 'top-N' return behavior, which relates to the 'limit' parameter. Overall, the schema carries the burden adequately, so a midrange score 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?

The description clearly states the action ('Find tools'), the resource ('tools'), and the mechanism ('by describing the data or task'). It enumerates the covered domains and explicitly distinguishes itself from data-retrieval siblings by focusing on tool discovery. The phrase 'Call this FIRST when you have many tools available' reinforces its unique role as an exploratory entry point.

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 explicit when-to-use guidance: 'Use when you need to browse, search, look up, or discover what tools exist' and 'Call this FIRST when you have many tools available and want to see the option set (not just one answer).' While it doesn't name specific alternative tools to use instead, the context makes the appropriate scenario clear, which justifies a score above the midrange.

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