get_domain

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

readOnlyHint=true already covers the safety profile, so the description's added value is disclosing the response payload - status, region, and the required DKIM/MAIL FROM DNS records. That tells an agent what it will actually receive, which matters since no output schema exists; it stops short of covering error behavior for an invalid or missing id.

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?

One sentence, verb-front-loaded, with zero filler. The return fields are listed compactly after the purpose statement.

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 single-resource read with no output schema, the description compensates by naming the returned fields, so an agent knows what to expect. Remaining minor gap is failure/not-found behavior, which is low stakes for a read-only lookup.

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?

Single parameter with 100% schema description coverage; the schema already defines the UUID format and states the id comes from list_domains. The description adds no further meaning about the parameter, 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 and resource ('Get one sending domain') and enumerates what the record contains (status, region, DKIM/MAIL FROM records). The singular 'one sending domain' implicitly separates it from the sibling list_domains, though the sibling is never 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?

Usage is only implied: retrieving a single domain by id is the obvious complement to list_domains, and the schema notes the id comes from list_domains. There is no explicit when-to-use, when-not, or named alternative in the description itself.

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