dossier_spf

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

Discloses key behavioral details: fetches via Cloudflare DoH, 5s timeout, locates v=spf1 record, parses mechanisms, and return format. No annotations exist, so the description carries full burden; it covers most aspects, though it could mention that the operation is read-only.

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 concise and front-loaded, with each sentence adding value. No redundant information.

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?

Covers purpose, usage, behavior, parameter, and return format. References sibling tools appropriately. No output schema, but the description fully describes the structure of the result.

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 single parameter 'domain' is well-described in the input schema (100% coverage) with constraints. The description adds no further parameter-specific detail beyond restating context, so score is at baseline given high schema coverage.

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 the tool's action ('retrieve and parse a domain's SPF record') and resource, and distinguishes it from siblings like dns_lookup for raw records and dossier_dmarc for full email-auth coverage.

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?

Explicitly provides usage scenarios (verify policy, debug failures, check lookup limit) and when to use alternatives (pair with dossier_dmarc for full coverage, use dns_lookup for raw record).

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