generate_dmarc_record

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

Annotations indicate readOnlyHint=true and idempotentHint=true, which are consistent with a tool that generates but does not publish. The description adds key behavioral details: the record is re-validated before return, and a human must approve before publishing. It also includes rules like 'never compose one yourself' and recommendations for parameter values.

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 extremely concise: two sentences plus a parameter summary. Every sentence adds value. The key action ('Build a DMARC record') is front-loaded, and warnings are placed prominently. No wasted words.

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?

Given no output schema, the description tells the agent to present the record verbatim and that a human must approve. Parameters are fully covered. Sibling tools are listed but not explicitly differentiated, though the context is sufficient. Minor gap: no explanation of what happens if the domain already has a record.

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 baseline is 3. The description goes beyond schema by summarizing parameters (policy, rua_email, etc.) and adding actionable guidance (e.g., 'start at none unless...', 'strongly recommended'). This adds meaningful context for the agent.

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 clearly states that the tool builds a DMARC record from scratch for a domain with none, using a validating engine. It distinguishes itself from siblings by explicitly saying 'never compose one yourself,' emphasizing that this is the automated, safe way to generate a record.

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?

The description provides strong usage guidance: 'for a domain that has none' and recommends starting with 'none' policy unless reports justify enforcement, and strongly suggests setting rua_email. However, it does not explicitly compare with sibling tools like build_dmarc_upgrade, leaving some ambiguity about when to use which.

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