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

Annotations already declare readOnlyHint=true, so the tool is known to be read-only. The description adds valuable behavior beyond that: it triggers an immediate DNS check instead of a background re-check, and it sets expectations that propagation delay is normal. It also implies the domain must be already connected. This is meaningful added context without contradiction.

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 very concise: a single opening sentence stating purpose, followed by two short sentences covering behavior and handling of results. It is front-loaded with the core purpose and contains no redundant or irrelevant information.

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 tool's low complexity, full schema coverage, readOnly annotation, and presence of an output schema, the description is complete. It covers what the tool does, the immediate-execution behavior, what to expect, and how to respond. No critical missing context.

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%, with both `domain` and `project` well-described in the input schema. The description itself does not add extra parameter semantics, but per the rubric, the baseline is 3 when schema covers all parameters, and the description doesn't need to compensate.

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 a specific verb+resource: 'Check whether a connected domain has started working.' It also specifies the action is a DNS check run immediately, which distinguishes it from sibling tools like `site_status` or `check_performance`.

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 usage context: it runs the DNS check immediately rather than waiting for the background re-check, implying when an immediate answer is needed. It also advises how to handle non-propagated records ('say so and suggest coming back later'). However, it doesn't explicitly name alternative tools or state when not to use it.

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