Increment a counter in the cache.
AI agents use cache_incr to create or update resources in AWS Documentation MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your AWS Documentation MCP Server environment.
The tool modifies cached data by incrementing a counter value. This is a reversible write operation — it changes state in the cache but does not irreversibly delete or overwrite data. The severity is medium because misuse could corrupt counter-based logic (e.g., rate limiting, session tracking), but it is not destructive or financial in nature.
From the tool's definition Increment a counter in the cache
Attacks that exploit this kind of access
Increment a counter in the cache. It is categorised as a Write tool in the AWS Documentation MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the AWS Documentation MCP Server MCP server in PolicyLayer and add a rule for cache_incr: 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 AWS Documentation MCP Server. Nothing to install.
cache_incr 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 cache_incr 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 cache_incr. 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.
cache_incr is provided by the AWS Documentation MCP Server MCP server (awslabs.aws-documentation-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.