Resend eSIM login code

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

Beyond the annotations (which only indicate non-read-only, non-idempotent, non-destructive), the description discloses critical behavioral constraints: the code goes to the same destination as the ongoing login, resend should only occur on explicit user request, and the agent must not auto-retry after failures. It also specifies how to respond to platform-reported rate limits or still-active codes.

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 compact and well-structured: it opens with the core action, then provides clear WHEN and DO NOT conditions. Every sentence contributes meaningful guidance, and there is no redundant or filler 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 presence of an output schema, rich parameter descriptions, and sibling context, the description fully covers the tool's purpose, usage triggers, exclusions, and failure-handling behavior. It is complete for safely selecting and invoking this resend operation.

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 already provides extremely detailed parameter descriptions (100% coverage), including exact-format requirements and warnings not to invent values. The description adds further value by emphasizing 'Pass the same email or phone that started the login,' which is a key semantic constraint not explicit in the schema.

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 function: 'Send the pending one-time code again, to the same destination as the login already in progress.' It distinguishes this from sibling tools like request_login_otp and verify_login_otp by emphasizing it resends a pending code rather than requesting or verifying one.

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 provides explicit when-to-use and when-not-to-use guidance: 'WHEN: only when the user explicitly asks for another code' and 'DO NOT call this on your own after a wrong or expired code, and do not use it to retry a failed request_login_otp.' It also instructs the agent to wait if the platform reports an active code or a limit was reached.

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