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

No annotations are supplied, so the description carries the full behavioral burden and mostly fails it. It never says what happens when no DKIM record exists, whether the key is parsed/validated versus merely returned, or what DNS failures look like. "Runs the same code the tool page runs" asserts consistency but conveys no actionable behavior.

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?

Very short, which is good, but the opening is a bare noun phrase rather than a front-loaded statement of action. "Runs the same code the tool page runs" occupies a third of the text without telling the agent anything it can act on.

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 no-annotation, no-output-schema tool, the description leaves out the essentials: whether the result is a raw key, a parsed record, or a pass/fail verdict, and how selector defaults work. Two schema parameters are covered, but the agent cannot predict the response shape from this text.

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 both parameters are already documented in the schema and the baseline applies. The description adds nothing beyond that, and notably does not explain what the tool does when the optional selector is omitted, which is the main ambiguity an agent faces here.

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?

"DKIM public key" names the resource but is a sentence fragment with no verb, so the agent must infer that the tool performs a lookup of the DKIM DNS record for a domain. It is distinguishable from most siblings (check_ssl, check_csp), but the relationship to check_dns, check_email_check, and check_mx is never clarified.

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 statement of when to use this instead of check_dns, check_email_check, or check_mx, nor any prerequisites such as needing the selector when the domain uses a non-default one. "Scope: dns" hints at the lookup layer but gives no routing guidance.

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