coin_change
Compute minimum coins for a target amount and count distinct combinations.
This record as markdown: /tools/io-github-malamutemayhem-unclick-mcp-server/coin-change.md
What coin_change does on UnClick
AI agents call coin_change to retrieve information from UnClick without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
coins | array | Yes | Coin denominations |
amount | number | Yes | Target amount (max 1,000,000) |
Parameters from the server's own tool schema.
Why coin_change is rated Low
Even though coin_change only reads data, uncontrolled read access leaks sensitive information and racks up API costs: an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.
Attacks that exploit this kind of access
The rule that runs coin_change safely
PolicyLayer is an MCP gateway: it sits between your AI agents and UnClick, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For coin_change, this is the rule to start with:
coin_change is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect UnClick, apply this rule, and every coin_change call is checked against it from then on.
Questions about coin_change
Compute minimum coins for a target amount and count distinct combinations. It is categorised as a Read tool in the UnClick MCP Server, which means it retrieves data without modifying state.
coin_change accepts 2 parameters: coins, amount. Required: coins, amount. The full parameter table on this page comes from the server's own tool schema.
Register the UnClick MCP server in PolicyLayer and add a rule for coin_change: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches UnClick. Nothing to install.
coin_change is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the coin_change rule in your PolicyLayer 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 PolicyLayer policy for coin_change. 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.
coin_change is provided by the UnClick MCP server (@unclick/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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