Purchase Disco credit packs using a stored payment method. Credits cost $1.00 each, sold in packs of 20 ($20/pack). Credits are used for private analyses (public analyses are free). Requires a payment method on file — use discovery_add_payment_method first. Args: packs: ...
Handles credentials or secrets (api_key)
Part of the Discovery Engine MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.
AI agents use discovery_purchase_credits to create or modify resources in Discovery Engine. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call discovery_purchase_credits repeatedly, creating or modifying resources faster than any human could review. Intercept's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Discovery Engine.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
tools:
discovery_purchase_credits:
rules:
- action: allow
rate_limit:
max: 30
window: 60See the full Discovery Engine policy for all 12 tools.
Agents calling write-class tools like discovery_purchase_credits have been implicated in these attack patterns. Read the full case and prevention policy for each:
Other tools in the Write risk category across the catalogue. The same policy patterns (rate-limit, validate) apply to each.
Purchase Disco credit packs using a stored payment method. Credits cost $1.00 each, sold in packs of 20 ($20/pack). Credits are used for private analyses (public analyses are free). Requires a payment method on file — use discovery_add_payment_method first. Args: packs: Number of 20-credit packs to purchase. Default 1. api_key: Disco API key (disco_...). Optional if DISCOVERY_API_KEY env var is set. . It is categorised as a Write tool in the Discovery Engine MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Add a rule in your Intercept YAML policy under the tools section for discovery_purchase_credits. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Discovery Engine MCP server.
discovery_purchase_credits is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the discovery_purchase_credits rule in your Intercept policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the Intercept policy for discovery_purchase_credits. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
discovery_purchase_credits is provided by the Discovery Engine MCP server (leap-laboratories/discovery-engine). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Open source. One binary. Zero dependencies.
npx -y @policylayer/intercept