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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is fully covered elsewhere. The description adds genuine context by noting the lookup is a public tool with no auth required, which is not in the annotations. It stops short of saying anything about latency, caching, or the shape of returned records.

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, zero filler, with the core action and record types front-loaded before the auth note. Every clause 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?

For a two-parameter, read-only lookup with rich annotations, the description covers what it does and the auth posture adequately. With no output schema, a brief hint about the response shape (e.g., one answer list per record type, empty when absent) would close the remaining gap.

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 100%, so both parameters are already documented, and the description merely echoes the record-type list. It actually introduces a small inconsistency: it advertises NS while the schema enumerates SOA, which could mislead an agent choosing a record type. Baseline 3 is appropriate given the schema carries the semantics.

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 ('Resolve') plus resource ('DNS records') and enumerates the record types returned, which is enough for an agent to identify the tool. It doesn't explicitly contrast itself with near-neighbors like vs_ssl_check or vs_website_check, so differentiation is inferred rather than stated.

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 only guidance offered is 'No authentication required,' which is a prerequisite note, not a when-to-use rule. There is no mention of when to prefer this over vs_ssl_check/vs_website_check or of any exclusions.

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