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

With no annotations, the description carries the burden of explaining behavior. It reveals that the tool reports aggregate shares and per-crawler breakdowns, and suggests a current-snapshot view with 'right now.' However, it does not clarify how 'served,' 'robots-blocked,' or 'edge-blocked' are determined, what data source or measurement window is used, or whether any operational constraints apply.

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 entire description is one focused, front-loaded sentence. It packs the metric's scope, blocking criterion, and per-crawler breakdown without filler or repetition.

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?

For a parameterless metric tool, the description conveys the main output and scope, and no output schema exists to fill gaps. Still, it leaves the exact meaning of the breakdown categories and the relationship to sibling tools like domain_readiness and edge_blocking unspecified, so an agent may need additional inference.

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?

The tool has zero parameters and 100% schema coverage, so there is no parameter documentation burden. The description appropriately focuses on output semantics rather than parameter details, which matches the baseline for a parameterless tool.

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 identifies the tool's subject: the share of measured top domains readable by AI assistants and a per-crawler breakdown of served, robots-blocked, and edge-blocked states. It is specific and distinct from the aggregate scope, though it lacks an explicit action verb like 'returns' or 'calculates'.

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 implies the tool is for assessing overall web openness across measured domains, but it never explicitly says when to choose this tool over siblings like domain_readiness or edge_blocking. There is no when-not-to-use guidance or named alternatives.

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