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

Annotations already declare readOnlyHint=true, so the description's 'Free, read-only' is partly redundant, but it goes further by describing the diagnostic output shape (per-record expected vs found, HTTPS state, actionable fix list) that no output schema supplies. It also clarifies the operator intent ('what to relay'), which helps the agent present results.

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?

Front-loaded with the core question ('Why a project's custom domain doesn't work yet'), followed by output contents, the usage rule, and a docs link. Every clause earns its place; the trailing URL is the only slightly expendable element.

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?

With no output schema, the description correctly takes on the burden of explaining what the tool returns, and it does so concretely. The remaining gap is the undocumented projectId, which is a minor omission for a single-parameter read-only diagnostic.

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 single projectId parameter has zero schema description coverage, so the schema does not explain it. The description only implies the subject ('a project's custom domain'), leaving the agent to infer that projectId selects that project. Adequate but not compensating for the coverage gap.

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?

States a specific verb (diagnose) and resource (a project's custom domain) and enumerates exactly what it reports: expected vs found DNS records, HTTPS issuance status, and a plain-language fix list. This is clearly distinguishable from the sibling lavela.provision_domain, which creates rather than diagnoses.

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?

Explicitly names the trigger condition and ordering: 'Use it after lavela.provision_domain.' That routes the agent to the correct lifecycle stage. It lacks any when-not-to-use or alternative-branch guidance, which keeps it short of a 5.

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