get_upgrade_linkA checkout link for a paid plan from the active payment provider: Starter ($24.99/month, 500 applications a month) or Pro ($49/month, 1,000 a month; the default). The person opens it in a browser to pay; the account upgrades automatically when the payment lands.
| Name | Required | Description | Default |
|---|---|---|---|
| plan | No |
Changes observed during successful MCP inspections.
Input schema / properties / planAdded value: +{
+ "enum": [
+ "starter",
+ "pro"
+ ],
+ "type": "string"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations only declare the mutation-ish flags (readOnlyHint=false, idempotentHint=false, destructiveHint=false). The description adds genuinely new behavioral context: the upgrade is asynchronous and external, completed only once the payment lands in the browser — a side effect an agent cannot infer from the flags.
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?
Two sentences, no filler, with the core deliverable front-loaded. The pricing detail is slightly heavy for a link tool but directly supports plan selection.
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?
No output schema exists, and the description does explain what the caller gets (a checkout link) and what happens after payment. For a single-optional-param tool this is nearly complete; only explicit alternative-tool routing is missing.
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 0%, so the description carries the burden. It documents the two enum values with prices and quotas and, importantly, states that Pro is the default, which the bare enum does not convey.
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 names a specific resource (checkout link) for a specific purpose (upgrading to a paid plan) and enumerates the two plans with prices, so an agent knows exactly what it returns. It does not explicitly distinguish itself from the sibling get_billing_portal_link, leaving that routing to inference.
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 explains how the link is used ('The person opens it in a browser to pay; the account upgrades automatically when the payment lands'), which implies the appropriate context, but there is no explicit when-to-use guidance or comparison against get_billing_portal_link / cancel_subscription.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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