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

Beyond the annotations (readOnly/openWorld/idempotent/non-destructive), the description discloses real behavior: it checks live DNS to show what is already in place, warns about clashes such as duplicate SPF records, and flags provider-generated values. That is meaningful operational context; it only stops short of noting rate limits or lookup failure handling.

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?

Three sentences, front-loaded with the deliverable before the live-check and warning behavior. Dense but each sentence carries information; slightly list-heavy with the parenthetical platform enumerations.

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 the return-value burden itself and does so — records to add, live DNS status, clashes, and marked per-account values. Combined with read-only annotations, an agent has what it needs; only the domain input format remains unaddressed.

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 only 25% (only 'account' is documented in the schema). The description partly compensates by grouping the enum values into website hosts vs email providers, clarifying what the 'website' and 'email' enums mean, and its line about account-generated values touches the 'account' param. It still says nothing about the required 'domain' parameter's expected format, so it doesn't fully close the 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?

The description names the specific output — the exact DNS records for a website host and an email provider, plus a DMARC policy — and enumerates the supported platforms, which map to the enum values. No sibling tool (all domain-marketplace names) does anything similar, so an agent can differentiate instantly.

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?

It gives clear context: use this when a domain needs to serve a website and receive email. It does not name alternatives or exclusions, but no sibling covers DNS, so the omission is minor and the usage window is unambiguous.

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