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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is well covered. The description adds useful behavioral context by defining the exact scope of measurements and explicitly listing excluded metrics, giving the agent realistic expectations about what the tool can report. No contradiction with 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?

Two sentences with no wasted words. The most important usage constraint is front-loaded, followed by a compact list of measured signals and a compact list of exclusions. Every sentence 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?

The description is complete enough for selecting and invoking the tool: it states the trigger condition, the measured signals, and the explicit limitations. The output schema is present, so return values need not be described in the text. Minor gap: 'bounded page' is not fully elaborated, and there is no mention of rate limits or failure modes, but annotations and schema cover the key safety and invocation aspects.

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 both parameters (url and language) are already documented with examples and constraints. The description does not add parameter-level detail, but it does clarify what the url will be checked for (robots, structured data, sitemap, llms.txt), which subtly informs how the url parameter is used. Baseline 3 is appropriate given the schema already carries the semantic weight.

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 uses a specific verb ('inspect a public website') and explicitly names the resource and signal categories measured: bounded page, robots, structured-data, sitemap, and llms.txt. It also clearly states what the tool does not measure, which removes ambiguity and distinguishes it from any broader analytics tool.

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 opening instruction 'Use only when a user asks to inspect a public website' gives an explicit triggering condition. The negative list ('does not measure AI mentions, rank, visibility, firewall passage, or sales') helps an agent avoid using it for those needs, though it does not name alternative tools for those cases. Siblings are catalog/order tools, so no direct site-check alternative is available to reference.

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