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

Annotations provide idempotency and non-destructiveness, and the description adds that the tool returns the record name, value, and type ready for DNS, which is useful given no output schema. It does not detail behavior for unsupported providers or external dependencies, but the openWorldHint annotation already suggests reliance on provider data.

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?

Two sentences with no fluff; the main action and output are stated first, making the description immediately understandable.

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?

The description covers the core purpose, the basis for generation (provider), and the output format, which is essential since there is no output schema. It lacks explicit error conditions for unknown providers, but the parameter descriptions cover the inputs adequately for a simple generator.

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?

The input schema contains 100% parameter descriptions, so the baseline is 3. The description adds no additional parameter semantics beyond restating the provider-based logic, and the schema already defines domain and hard_fail_boolean clearly.

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 uses the specific verb 'Generate' with a clear resource ('SPF DNS record') and scope ('based on the email provider being used'), distinguishing it from sibling check tools like spf_check and from dmarc_generate by naming the record type explicitly.

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 clearly indicates when to use the tool ('based on the email provider being used') and what it produces. However, it does not explicitly mention alternative tools or exclusions, such as 'use dmarc_generate for DMARC records,' so it falls short of full usage guidance.

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