Check DMARC Readiness

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

Annotations already declare readOnly/idempotent/non-destructive, and the description layers on auth requirement (API token), null-while-blocked semantics ('THAT NULL IS AN ANSWER'), human approval requirement, and the record_withheld/hosted branches. These are non-obvious behaviors an agent must relay correctly, going well beyond the annotation set.

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?

Front-loaded with the when-to-use trigger and core verdict, then progressively details edge cases. Dense and mostly earns its length, though the hosted/record_withheld branches make it long enough that a reader must track several clauses.

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?

No output schema exists, and the description fully enumerates the return shape (ready flag, blockers, window, next_record/null, record_withheld, withheld_reason, hosted). An agent has everything needed to call and correctly relay results.

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% and the schema already explains the verified-monitored-domain restriction and not-found behavior. The description reinforces 'ONE domain the caller's account monitors' but adds no new syntax. Baseline 3 plus marginal reinforcement puts this at 4.

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 (read/check readiness) and resource (DMARC enforcement-readiness verdict for one domain), scoped to the account's monitored domains. It distinguishes itself from scan_domain ('a scan can show a domain's current policy, but only this evidence window can say whether tightening it would start rejecting real mail').

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?

Explicit trigger: 'Use this when a signed-in operator asks whether a monitored domain is ready for the next DMARC step.' Plus a when-to-use-before rule ('before proposing enforcement') and a named alternative with the differentiating condition against scan_domain.

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