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

Goes beyond the provided annotations by adding useful behavioral context like the expected response time ('Takes roughly 2-8 seconds') and a note about using the tool as 'grounding' before advising on changes. It doesn't contradict the read-only and idempotent annotations.

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?

Perfectly sized. Three sentences, each with a distinct purpose: what the tool does, when to use it, and what to expect in terms of performance. Every sentence earns its place, and the information is structured logically.

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?

The description is perfectly complete for a tool with only two simple parameters and no complex return types. It thoughtfully covers the functionality, provides examples for the parameter, and explicitly acknowledges the existence of a sibling tool without going into unnecessary depth about it.

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?

While the schema already covers most of the descriptive burden with 100% coverage, the description adds excellent VALUE BEYOND that, particularly for the 'url' parameter with the real-world example that a bare domain is treated as https. This proactive clarification is exactly what a helper should do.

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 is exceptionally clear with a strong verb and resource ('Run the full 200-check audit of a website'). It explicitly distinguishes itself from siblings by mentioning the use case for broad questions and specifically names the alternative 'check_category' for narrower queries.

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?

Offers explicit trigger phrases and when-to-use guidance. It also provides a clear alternative ('If the user only cares about one area, check_category is faster') and notes the trade-off in terms of speed and output size, which is invaluable for an agent to select the right tool.

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