Get verification code

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

The annotations (readOnlyHint=false, destructiveHint=false) leave the non-read-only side effect unexplained, and the description fills that gap: copy_to_clipboard writes to the user's clipboard, is concealed from clipboard managers, and is auto-cleared. It also discloses latency expectations (max 45s wait, ~1s with watcher) and retry semantics. It doesn't mention auth/permission requirements, so not a full 5.

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 core purpose leads the first sentence and each following sentence carries operational information (waiting, retry, watcher, clipboard). The closing sentence about the code being returned 'by design' is marginally redundant given the output schema exists, which keeps it from a perfect score.

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 five-parameter, zero-required tool with full schema coverage and an output schema, the description covers timing, retry, performance modes, side effects, and result format adequately. The one thin spot is that it references '[settings.watcher]' without directing the agent to the related configuration sibling.

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 the baseline is 3; the description goes beyond it by explaining clipboards concealment and auto-clearing for copy_to_clipboard, plus the retry meaning of wait_seconds. It adds real semantic value rather than merely restating schema text, though account/mailbox/lookback_minutes get no extra description.

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 states a specific verb and resource ('Find the newest verification code (OTP/2FA) or sign-in magic link in recent mail') and even names the detection method. This is clearly distinct from generic siblings like search_emails, get_email, or get_emails, so an agent can route to it without opening a schema.

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 gives concrete operating conditions: use wait_seconds for mail still in flight, simply call again if nothing arrives, and it contrasts polling vs. watcher-enabled behavior (~1 second hits). What's missing is an explicit pointer to a sibling (e.g., configure_verification for watcher setup) or a statement of when NOT to use this tool, so it stops short of 5.

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