Switch the project owner between Pro and Scale, or cancel the subscription (effectively dropping to Free at period end). Returns {kind, newPlan, effectiveAt, applied} — applied=true means Paddle was charged immediately, otherwise the change is queued for the current period end. Use preview_plan_change first to see the dollar impact. Owner-only; requires a token minted with the billing scope.
| Name | Required | Description | Default |
|---|---|---|---|
| plan | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description explains the return format with {kind, newPlan, effectiveAt, applied} and details the behavior of `applied` (immediate charge vs queued). It also discloses that canceling drops to Free at period end. This goes well beyond the annotations (destructiveHint=true) to give a full picture of the action's effects and timing.
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 that are tightly packed with information: action, return value, and usage guidance. No wasted words; every clause serves a 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?
Despite having only one parameter and no output schema, the description covers the action, effect, timing, return semantics, prerequisites, and suggested prior step. It is fully self-contained for an agent to select and invoke the tool correctly.
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 description adds meaningful context to the single 'plan' parameter by mapping values to actions (Pro/Scale switch, free = cancel). Although it doesn't explicitly enumerate the enum values, it explains their practical effect. Since schema coverage is 0%, this compensation is valuable but not exhaustive.
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 function with specific verbs ('Switch', 'cancel') and resources ('project owner between Pro and Scale', 'subscription'). It also distinguishes from sibling tools like preview_plan_change by explicitly positioning this as the actual change action.
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 provides explicit guidance to use preview_plan_change first to see the dollar impact, and states prerequisites (owner-only, billing scope token). This clearly indicates when to use the tool and what is needed, differentiating it from related alternatives.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Most tools target distinct resources and the descriptions are unusually explicit, but the billing cluster (change_plan/cancel_subscription and the many add-on actions) plus the preview/diff tools overlap and could cause mis-selection. config_diff, dry_run_endpoint, and preview_line_draft all read as 'preview what will change' at first glance despite different scopes.
The overwhelming majority follow a clean snake_case verb_noun pattern: create_*, get_*, list_*, set_*, update_*, delete_*. It is only held back by a few naming outliers such as config_diff and default_endpoint_template, which break the verb-first convention.
78 tools is an extreme mismatch for an MCP server surface, even accounting for the broad management/relay domain. Such a large surface will overwhelm model context and make tool selection materially harder; this would be better split into focused servers for configuration, data-plane operations, and billing.
The tool surface is very thorough: projects, lines, endpoints, credentials, keys, configs/drafts, DLQ, requests, metrics, audit, team, and billing are all represented. Only minor gaps exist, such as no direct single-line get/update and the intentional inability to widen the outbound allowlist or lift archive protection via API.
