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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds that the payload is the raw/original XML rather than a parsed summary, which is genuinely useful since there is no output schema, but says nothing about size, encoding, or failure modes.

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 or repetition. It is efficient, though so terse that it borders on under-specification rather than optimal conciseness.

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 simple two-parameter read-only fetch, the description covers the essential what and the output format (XML, which matters absent an output schema). It is missing the organizationId meaning and any hint about retrieving the report ID first, leaving an agent to consult sibling schemas.

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 only 50%: reportId is documented in the schema (sourced from get_dmarc_records), but organizationId has no description anywhere. The tool description adds no parameter meaning at all, so it fails to compensate for the uncovered organizationId.

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 states a specific verb + resource ('Download a DMARC report') and adds scope ('original XML'), which helps distinguish it from the sibling get_dmarc_records that returns parsed records. It stops short of explicitly naming that sibling as the source of the report data.

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?

There is no guidance on when to use this versus get_dmarc_records, no mention that the report must already exist, and no prerequisites or exclusions. Only the schema's reportId description hints at the relationship to get_dmarc_records.

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