DKIM Record Check

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

Annotations already indicate readOnlyHint, idempotentHint, and openWorldHint. The description adds critical behavioral context: the probing of common selectors when none are provided and the inconclusiveness of a miss. It also describes the return structure.

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 about 100 words, well-structured with bullet points for args and returns, and front-loaded with the core purpose. No unnecessary content.

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 the moderate complexity (3 parameters, output schema present), the description covers all necessary aspects: purpose, behavior, parameter details, return format, and examples. No gaps.

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 schema provides full descriptions for all three parameters (100% coverage), so baseline is 3. The description adds value by explaining the probe behavior for selectors and noting the default for response_format, making the semantics clearer than schema alone.

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 it looks up DKIM public keys with the specific query pattern <selector>._domainkey.<domain>. It distinguishes itself from siblings like dmarc_check and spf_check by focusing solely on DKIM.

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?

It explains when to use the tool—to check DKIM—and provides guidance on selectors: users should pass specific selectors for a definitive answer, and if omitted, a miss is inconclusive. It doesn't explicitly compare to sibling tools, but the sibling context makes it clear.

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