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

With no annotations provided, the description carries the behavioral burden. It clearly discloses that the tool performs 9 real outbound HTTP requests, lists the user-agent composition and resource types, and indicates that results come from a fresh measurement rather than cached data. It does not mention potential latency, rate-limit considerations, or whether results are persisted, but the core behavioral profile is well disclosed.

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?

Three sentences, each earning its place: the first defines the action precisely, the second gives usage direction, and the third explains the return value. There is no filler or duplication of schema content.

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 the absence of an output schema, the description adequately explains the return by referencing the same `fixes` list as domain_readiness. It also supplies the request composition, usage conditions, and the distinction from archive data. It could be more complete by describing what the fixes list contains, but it is sufficient for an agent to invoke the tool correctly.

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 both parameters (host and force) are already fully described in the input schema. The description adds useful context about when a fresh measurement matters (after robots.txt/WAF changes), but it does not materially extend the parameter semantics beyond what the schema already provides. Baseline 3 applies.

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 opens with a specific verb and resource ('Measure a domain') and immediately differentiates the tool from its archive-based alternative ('instead of reading the archive'). It also enumerates the exact measurement behavior (9 HTTP requests, specific user-agents, and resource types), so an agent clearly knows what this tool does and how it differs from domain_readiness.

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?

It gives explicit when-to-use guidance: 'Use it for any site the index has not reached yet, or when the caller wants a fresh verdict after changing robots.txt or a WAF rule.' It also states the alternative behavior ('instead of reading the archive'), which helps the agent choose between this tool and the archive-based sibling.

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