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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It says it "Returns the answer records" but is silent on lookup failure behavior (NXDOMAIN, timeouts), whether results are cached, and whether it reaches the public resolver or an internal one. The `locale` parameter's effect on behavior is never explained.

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 short, front-loaded sentences with no padding; the core action leads. The closing "Use to check DNS" is redundant with the opening sentence and could be dropped, but the overall shape is tight.

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 three-parameter lookup with no annotations and no output schema, the description covers the essentials of calling it. It stops short of describing the response structure or failure modes, leaving the agent to guess what to do when a lookup returns nothing or errors.

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 coverage is 0%, so the description must carry the load, and it does for two of three parameters: it clarifies `name` as a domain and enumerates valid `type` values (A/AAAA/CNAME/MX/TXT/NS) that appear nowhere in the schema. It omits `locale` entirely, which keeps this from being a 5.

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 ("Resolve DNS records") along with the inputs and the shape of the return ("answer records"), so an agent knows exactly what the tool produces. The sibling list contains only unrelated utilities (hash-generator, world-clock, etc.), so no differentiation is possible or needed.

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?

"Use to check DNS" restates the purpose rather than giving real guidance — there are no prerequisites, no when-not conditions, and no alternatives named. Usage is only implied, which is the definition of a 3.

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