Start sign-up

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

The description discloses behavior beyond the annotations: Andru emails a 6-digit code and an Approve button, the caller must handle either code verification or approval polling, and the resulting key is returned through signup_status. It also explains the initial spend limit default, which is important operational context for an otherwise non-read-only tool.

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 front-loaded with the trigger condition and the core action, then follows the branching flow efficiently. It is mostly concise, though the final sentence about spend limits is slightly tangential and not tied to any input parameter.

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 multi-step sign-up flow with no output schema, the description covers the key branches and the verification/polling sequence well. It does not explicitly state what signup_start itself returns, though the need for request_id in the next step is implied.

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%, so all five parameters are already well documented by the input schema. The description reinforces that the email is where the code goes, but it does not add meaningful semantics for website, foundVia, agentName, or previewId beyond what the schema already says.

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 action: starting Andru sign-up or sign-in by sending the person's email. It clearly distinguishes this tool from the follow-up siblings signup_verify and signup_status by explaining which path to take depending on whether the user reads a code or taps Approve.

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 explicitly says when to use this tool: when the person asks to sign up for or sign in to Andru from here. It also names the alternatives and the exact conditions for choosing signup_verify versus signup_status, including polling signup_status until it returns the key.

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