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

The description discloses key behavioral traits beyond annotations: the two-step verification flow, that the key is only released after link click, that the key is shown only once, and that the trial is upgraded in place. It also mentions the free tier limit and pricing URL. This adds significant context beyond the annotations (readOnlyHint=false, idempotentHint=true, etc.) and does not contradict them.

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 well-structured and front-loaded: it starts with the core purpose, then explains the two-step flow, then covers edge cases and constraints. Every sentence adds value, and the length is appropriate for the complexity of the tool.

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 tool's complexity (two-step verification, one-time key release, in-place upgrade), the description covers all necessary aspects: how to call it, what to expect, what to do after, and important caveats. No output schema exists, but the description explains the return values ('status: pending_verification' and the API key).

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 schema already documents both parameters. The description adds meaning by explaining the email's role in the verification flow and warning against using a made-up email. It also clarifies the 'name' parameter defaults to the local part of the email. This goes beyond the schema's basic descriptions.

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: converting a keyless trial into a real account and obtaining a permanent API key. It uses a specific verb ('create') and resource ('account'), and the title reinforces this. It distinguishes itself from siblings by focusing on account creation rather than template/render operations.

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 step-by-step usage: call once with email, wait for verification link click, call again with same email to get the key. It also states when not to use it (e.g., not for trial operations) and mentions the in-place upgrade preserving trial data. This is clear guidance for an agent.

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