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

Annotations already flag destructiveHint=true and readOnlyHint=false, so the description is not obligated to restate that. It does add genuinely useful behavior beyond the annotations: the mailCritical refusal guard, the reason (breaking domain email), and the required auth scope.

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 tight sentences with no padding: action first, then the guard/threshold, then the auth prerequisite. Every sentence carries information an agent needs.

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 destructive, unannotated-output tool this covers the essentials: scope, refusal behavior, and consequence. It could mention irreversibility or what a successful delete returns, but with no output schema that omission is minor.

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 100%, so the baseline is 3. The description goes further by explaining the semantics of force as a confirmation for mail-critical deletion, which is the one parameter whose meaning is not obvious from the schema alone.

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 (Delete) and resource (DNS record) and scopes it to a domain's live zone, which distinguishes it from create_dns_record/update_dns_record without requiring the schema. An agent can select it immediately.

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?

Explains a key condition for use: mailCritical records are refused unless force=true, and dns:write scope is required. It does not name an alternative tool (e.g., update_dns_record) for the 'I only wanted to change it' case, but the operating context is clear.

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