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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, but the description adds meaningful behavioral context: it issues nothing, it reports whether the record was OBSERVED as published, and it requires printing record host/value EXACTLY as returned without rewriting. It also clarifies that records are published by a human, not by this tool. No contradiction with annotations.

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?

The description is front-loaded with the core purpose, followed by the key alternative and the critical output and safety constraints. Each sentence earns its place; there is no filler or repetition of the schema. The exact-printing instruction and the human-approval caveat are both essential for correct agent behavior.

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-parameter read tool with rich schema coverage, output schema available, and annotations covering read-only/idempotent safety, the description adds the remaining critical context: the conditional call to check_domain_verification, the observed-published distinction, exact-output handling, and the human-approval workflow. Nothing needed for correct invocation is missing.

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?

There is only one parameter and the schema description covers it 100%, including what values are acceptable and how different callers relate to the domain. The description does not need to add parameter details; the schema already carries the full meaning. A baseline 3 is appropriate because the description adds no additional parameter-level semantics beyond the schema.

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 opens with a specific verb and resource: 'Read the records a domain the user monitors still needs', and then defines exactly which records are involved (ownership check, DMARC reporting record, observed-published status). This clearly distinguishes the tool from siblings like check_domain_verification, which issues records rather than reading them.

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?

It explicitly states when to use this tool versus check_domain_verification: 'if a verified domain comes back with no reporting record yet, call check_domain_verification once, which issues it.' It also warns that no DNS changes should be made without human approval, which is practical usage guidance beyond the read-only annotations.

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