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

Annotations already cover the safety profile: read-only, idempotent, non-destructive, and closed-world. The description adds useful output-scope context by naming the DNS and email-auth records returned, but it does not explain whether results are live DNS checks or stored configuration.

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 a single economical sentence that lists the relevant record types and the domain scope without filler. It could be slightly more front-loaded with an explicit verb, but every phrase earns its place.

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 needs to describe return values. It names the record types and the per-domain scope, which is adequate for selection, but it omits result structure and whether this is an aggregated health summary versus raw records.

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 tool takes zero parameters, so there is no parameter semantics to document beyond the schema. Baseline score of 4 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 clearly identifies the returned data (SPF, DKIM selector, DMARC policy, MX) and the scope (every connected domain). It is distinguishable from per-domain siblings like check_spf and check_dmarc, though it could state the verb more 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?

There is no explicit guidance on when to use this aggregate health view versus the individual check_spf, check_dkim, or check_dmarc tools. Usage is only implied by the phrase 'for every domain you have connected'.

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