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

With no annotations, the description must carry the behavioral burden. 'Get details' implies a read-only operation, and 'Requires authentication' discloses a precondition. It lacks explicit statements about lack of side effects, return shape, or error behavior, but for a simple read tool this is acceptable.

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 short sentences contain all essential information: purpose, authentication requirement, and required parameters with an example. There is no fluff or redundancy, though 'Required:' partially restates the schema's required array.

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 simple 3-parameter read tool with no output schema, the description covers purpose, authentication, and required args, including a domain format example. It could note how to obtain recordId (e.g., from listDnsRecords), but the param name and sibling tool make this inferable.

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 33%, so the description must compensate. It adds a concrete domain format example, but for recordId it merely repeats the string type without semantic context such as where the ID comes from. sessionKey is already well-described in the schema, so the description adds little over the structured data.

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 uses a specific verb ('Get') and resource ('details of a specific DNS record'), clearly indicating a single-record read operation and distinguishing it from listDnsRecords or mutation tools. It does not explicitly name a sibling or contrast itself, so it stops short of the strongest possible differentiation.

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 description states prerequisites: authentication is required, and both domain and recordId must be supplied. It gives a useful domain format example, but does not explain when to choose this tool over listDnsRecords or describe any exclusion conditions, leaving usage guidance mostly implicit.

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