Lists subscribers for a Gumroad subscription product with optional email filter, requiring access token and product ID.
List subscribers for a Gumroad membership/subscription product.
| Name | Required | Description | Default |
|---|---|---|---|
| No | Filter by subscriber email | ||
| product_id | Yes | Product ID of the subscription product | |
| access_token | Yes | Gumroad access token |
Changes observed during successful MCP inspections.
v0.1.11Input schema / properties / access_tokenAdded value: +{
+ "description": "Gumroad access token",
+ "type": "string"
+}Input schema / properties / api_keyRemoved value: -{
- "description": "Gumroad access token",
- "type": "string"
-}Input schema / requiredPrevious value: -[
- "api_key",
- "product_id"
-]New value: +[
+ "access_token",
+ "product_id"
+]v0.1.9v0.1.5Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description adds the useful constraint that the product must be a membership/subscription type, but says nothing about pagination, result size, or token requirements.
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?
One front-loaded sentence with no wasted words. It is efficient, though perhaps too terse to carry any operational detail.
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 simple read-only list tool with fully documented params and rich annotations, the description is minimally sufficient. It omits return shape and pagination behavior, which matters for a list endpoint with no output schema.
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 three parameters including the email filter are fully documented in structured data. The description only reinforces that product_id refers to a subscription product, adding marginal value over the schema.
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?
States a specific verb (List) and resource (subscribers) scoped to Gumroad membership/subscription products. It is distinguishable from gumroad_list_products and gumroad_list_sales by resource, though it never names those siblings explicitly.
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?
No guidance on when to use this versus other Gumroad tools, and no prerequisites stated (an access token and product ID are required). The membership/subscription qualifier implies the product must be a subscription product, but that is left to inference.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.