upgrade_to_pro

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

Given no annotations, the description carries full burden. It discloses the return value (Stripe Checkout URL), the required user action (open in browser), and the post-payment effect (automatic upgrade). It does not mention auth or rate limits, but for a simple upgrade tool this is sufficient.

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 sentences long: first sentence states purpose and benefits, second explains the return and user action, third confirms the automatic effect. Every sentence adds value with no redundancy, and it is front-loaded with the key purpose.

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?

With no parameters, output schema, or annotations, the description covers the essential aspects: what the tool does, what it returns, how the user should proceed, and the outcome. It could mention prerequisites (e.g., existing account, not already Pro), but is otherwise complete.

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 has zero parameters, so there is nothing to document. The description does not need to add parameter info, and the baseline score for 0-param tools is 4.

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 that this tool upgrades to the Pro plan, lists key benefits ($19/month, unlimited QR codes, scans, webhooks), and differentiates from sibling tools like 'manage_billing' which handle other billing aspects. It uses a specific verb ('Upgrade to the Pro plan') and a clear resource ('Pro plan').

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 guidance: returns a Stripe Checkout URL that the user should open in their browser to complete payment, and the upgrade takes effect automatically. It does not mention alternatives or when not to use it, but the context (only one upgrade tool) makes the usage clear.

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