# Polar MCP by usefulapi (io.usefulapi/polar-sh): tool descriptions scored

- tools/list taken: 2026-11-02 (UTC)
- From: [Official MCP Registry](https://registry.modelcontextprotocol.io/v0/servers/io.usefulapi%2Fpolar-sh/versions/latest)
- Connected to: https://polar-sh.usefulapi.io/mcp
- Homepage: https://usefulapi.io/polar-sh/
- Repository: https://github.com/m190/usefulapi-mcp
- Scoring rules: v2
- Tools: 26
- Average: 42.1 / 100 (Cloudy)
- Near-identical pairs: 0

This page shows how Polar MCP by usefulapi (io.usefulapi/polar-sh)'s tool descriptions scored, the issues found and the names of its tools and parameters. The descriptions are the server's own: read them where the copy came from.

Forecall asked the URL this server lists in the official MCP Registry for its tools/list once, on the date above, without calling any tool. The server may have changed since.

## Across the server

- Minor: 26 tools. Above 25, models start to tell tools apart less well.

## Tools

- `polar_list_discounts`: 35 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: No `required` list, so every argument is optional.
  - Minor: The description mentions none of its 3 or more arguments.
  - Minor: Says nothing about what it returns.
- `polar_list_customers`: 39 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: No `required` list, so every argument is optional.
  - Minor: Says nothing about what it returns.
- `polar_list_events`: 39 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: String arguments with no constraint or example: start_timestamp, end_timestamp.
  - Minor: No `required` list, so every argument is optional.
  - Minor: Says nothing about what it returns.
- `polar_list_meters`: 39 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: No `required` list, so every argument is optional.
  - Minor: The description mentions none of its 3 or more arguments.
  - Minor: Says nothing about what it returns.
- `polar_list_products`: 39 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: No `required` list, so every argument is optional.
  - Minor: Says nothing about what it returns.
- `polar_list_refunds`: 39 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: No `required` list, so every argument is optional.
  - Minor: The description mentions none of its 3 or more arguments.
  - Minor: Says nothing about what it returns.
- `polar_list_subscriptions`: 39 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: No `required` list, so every argument is optional.
  - Minor: Says nothing about what it returns.
- `polar_list_webhook_endpoints`: 39 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: No `required` list, so every argument is optional.
  - Minor: The description mentions none of its 3 or more arguments.
  - Minor: Says nothing about what it returns.
- `polar_list_license_keys`: 40 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: No `required` list, so every argument is optional.
  - Minor: Says nothing about what it returns.
- `polar_cancel_subscription`: 42 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: The description mentions none of its 3 or more arguments.
  - Minor: Says nothing about what it returns.
  - Minor: Required identifiers whose description does not say where the value comes from: subscription_id. Name the tool or the place that returns it, or models look it up first.
- `polar_create_checkout_link`: 42 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: Says nothing about what it returns.
- `polar_get_customer`: 42 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: Says nothing about what it returns.
  - Minor: Required identifiers whose description does not say where the value comes from: customer_id. Name the tool or the place that returns it, or models look it up first.
- `polar_get_order`: 42 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: Says nothing about what it returns.
  - Minor: Required identifiers whose description does not say where the value comes from: order_id. Name the tool or the place that returns it, or models look it up first.
- `polar_get_product`: 42 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: Says nothing about what it returns.
  - Minor: Required identifiers whose description does not say where the value comes from: product_id. Name the tool or the place that returns it, or models look it up first.
- `polar_get_subscription`: 42 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: Says nothing about what it returns.
  - Minor: Required identifiers whose description does not say where the value comes from: subscription_id. Name the tool or the place that returns it, or models look it up first.
- `polar_list_benefit_grants`: 42 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: The description mentions none of its 3 or more arguments.
  - Minor: Says nothing about what it returns.
  - Minor: Required identifiers whose description does not say where the value comes from: benefit_id. Name the tool or the place that returns it, or models look it up first.
- `polar_get_meter_quantities`: 43 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: The description mentions none of its 3 or more arguments.
  - Minor: Says nothing about what it returns.
  - Minor: Required identifiers whose description does not say where the value comes from: meter_id. Name the tool or the place that returns it, or models look it up first.
- `polar_get_metrics`: 43 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: Says nothing about what it returns.
- `polar_create_refund`: 44 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: The description mentions none of its 3 or more arguments.
  - Minor: Says nothing about what it returns.
  - Minor: Required identifiers whose description does not say where the value comes from: order_id. Name the tool or the place that returns it, or models look it up first.
- `polar_list_benefits`: 44 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: String arguments with no constraint or example: query.
  - Minor: No `required` list, so every argument is optional.
  - Minor: The description mentions none of its 3 or more arguments.
  - Minor: Says nothing about what it returns.
- `polar_list_orders`: 44 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: No `required` list, so every argument is optional.
  - Minor: Says nothing about what it returns.
- `polar_list_organizations`: 44 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: No `required` list, so every argument is optional.
  - Minor: Says nothing about what it returns.
- `polar_list_webhook_deliveries`: 44 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: String arguments with no constraint or example: start_timestamp, end_timestamp.
  - Minor: No `required` list, so every argument is optional.
  - Minor: The description mentions none of its 3 or more arguments.
  - Minor: Says nothing about what it returns.
- `polar_redeliver_webhook_event`: 44 / 100
  - Minor: Says nothing about what it returns.
  - Minor: Required identifiers whose description does not say where the value comes from: event_id. Name the tool or the place that returns it, or models look it up first.
- `polar_get_customer_state`: 50 / 100
  - Major: Says nothing about when to use it, or when not to.
  - Minor: Says nothing about what it returns.
  - Minor: Required identifiers whose description does not say where the value comes from: customer_id. Name the tool or the place that returns it, or models look it up first.
- `polar_get_customer_state_by_external_id`: 52 / 100
  - Minor: Says nothing about what it returns.
  - Minor: Required identifiers whose description does not say where the value comes from: external_id. Name the tool or the place that returns it, or models look it up first.

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