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

Annotations only declare readOnlyHint=false and destructiveHint=false; the description adds the rate limit (3 requests per minute) and the authentication/session requirement, which are exactly the extra behavioral facts an agent needs. It does not describe return behavior, but for a resend it adds solid value beyond the annotations.

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 purpose is front-loaded in one sentence, followed by the rate limit and access instructions — no filler. The ACCESS block is slightly verbose but every clause (account requirement, two auth paths) carries actionable 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?

For a simple two-parameter resend tool with no output schema, the description covers purpose, rate limits, and the authentication flow needed before invocation. The only meaningful gap is routing guidance relative to sibling verification-resend tools.

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 description coverage is 100% for both parameters, including the enum of permitted email_prefix values, so the schema carries the parameter burden. The description adds nothing about the id or email_prefix semantics, warranting the baseline 3.

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 first sentence states a specific verb+resource ('Resend the domain verification email'), which is clear and actionable. However, it does not distinguish this from close siblings such as resend_verification, resend_email_otp, or start_domain_email_verification, leaving the agent to infer the boundary.

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 ACCESS paragraph usefully describes prerequisites (Proof account, authenticate via /mcp or start_login, then call again), which is genuine when/how guidance. But it never states when to choose this tool over the many sibling resend/verification tools, so the selection guidance is only implied.

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