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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds only that reports are 'received for a domain,' saying nothing about volume, pagination behavior, default ordering, or date-range defaults — useful context for a list tool with 11 parameters but not a critical gap given annotation coverage.

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?

A single front-loaded sentence with no filler. It is efficient, though its brevity leaves little room for routing or behavioral context.

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?

With 11 parameters, no output schema, and a rich nested filters structure, the description gives no information about result shape, pagination interaction between page/limit/offset, or filter combination behavior. For a moderately complex list tool, this is under-described.

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 73%, so most parameters (date range, pagination, type, match, filters, org_name) are documented in the schema. The description mentions no parameter semantics at all, so it does not compensate for the undocumented remainder (status, offset, and the type enum's lack of description). Baseline 3 is appropriate.

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 (list) and resource (DMARC aggregate or forensic reports) scoped to a domain, which is clearer than the name alone. It does not distinguish itself from the close siblings list-dmarc-forensic-reports or get-dmarc-report, so an agent must infer that this is the broader version covering both report types.

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?

No guidance on when to use this versus list-dmarc-forensic-reports, get-dmarc-report, or get-dmarc-stats. The only usage signal is implicit in the phrase 'aggregate or forensic,' which the schema's type enum already conveys.

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