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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the notion of "stateless changes" and evidence-only output, but never explains why idempotentHint=false (repeated calls may differ) or what network/rate-limit behavior to expect from an open-world probe.

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 front-loaded sentences with the verb and scope stated first. The long enumeration of 11 checks is dense but earns its place by defining coverage; nothing is redundant.

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 two-param, read-only inspection tool with an output schema and annotations carrying the safety profile, the description covers scope and return nature adequately. The one gap is absence of guidance on the stateless-change flow (passing previous_state), which affects correct invocation ordering.

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 both the domain (including the localhost/IP rejection rule) and previous_state parameters are fully documented in the schema. The description adds no syntax or format detail beyond that, so 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 ("Inspect") and resource ("consolidated domain health") and enumerates the covered surface (DNS, TLS, MX, SPF, DMARC, email posture). This clearly differentiates it from narrow siblings like email_validator_basic or url_clean_content, though it doesn't name an alternative outright.

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 phrase "in one machine-to-machine call" implies the consolidation benefit versus making many separate checks, but there is no explicit when-to-use/when-not or named alternative. Usage is inferred rather than stated.

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