prepare_junk_email

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

With no annotations, the description carries the full burden and does well: it discloses that the tool returns a preview and an approval token, that the token expires after 5 minutes, and that an error is returned for non-existent email IDs. It implicitly conveys that no mutation occurs until confirmation.

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 three concise sentences, front-loaded with the purpose. Each sentence delivers essential information: the action, the return value, the next step, and token expiry. There is no wasted wording.

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?

As a preparation step in a two-phase operation, the description covers the essential context: what it returns, how to proceed, and error/expiry behavior. It does not detail the preview content or mention permissions, but these are not critical for correct invocation. With no output schema, this is sufficient.

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 fully describes the single parameter email_id, including type, constraints, and source examples. The description adds no additional parameter semantics beyond restating the email ID, so with 100% schema coverage, a baseline of 3 is appropriate.

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 purpose: to prepare an email for marking as junk (move to Junk folder). It distinguishes from the actual execution step by explicitly naming confirm_junk_email as the follow-up, using a specific verb ('prepare') and resource ('email').

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 clear usage context by describing the two-step workflow: call this tool to get a token, then call confirm_junk_email with that token. It does not explicitly list alternatives, but the naming and flow make the intended usage evident.

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