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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: first generation is slow, results are cached, and (via the schema) refresh bypasses the cache at a quota cost. Quota/rate specifics are only found in the schema, not the description.

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 tightly packed sentences: purpose and scope first, then the latency/caching caveat. No filler, and the operational warning is placed where an agent will read it before invoking.

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 carries return-value burden and does state the report covers DNS, email, TLS and headers with a score and grade. It stops short of describing report structure or the response envelope, but that gap is small for a read-only report generator.

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 domain, locale and refresh are already fully documented, including enum values and the quota consequence of refresh. The description adds only the cache context that indirectly explains the refresh flag, so the 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?

States a specific verb (generate) and resource (comprehensive domain health report), and enumerates the covered aspects (DNS, email, TLS, web/security headers) plus the output artifact (0-100 score and grade). This implicitly separates it from the single-aspect siblings (dns_query, tls_check, http_check), though no sibling is named explicitly.

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 caching note and 'slow on first generation' hint at when the tool is worth invoking and how to handle repeat calls, but there is no explicit when-to-use or when-to-prefer-a-narrower-check guidance relative to dns_query/tls_check/http_check. Usage is implied rather than stated.

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