AI agents call a2a_task_query to retrieve information from Wmux without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs a query operation that retrieves task information based on filters. It has no capacity to modify, delete, or execute actions—it only reads and returns data. The polling mechanism with timestamps is a standard read pattern. Severity is low because query results alone cannot cause harm; impact depends entirely on how the data is used downstream.
From the tool's definition Tool name 'a2a_task_query' and description 'Query tasks assigned to you or sent by you. Filter by status and role' indicate a read-only retrieval operation.
Attacks that exploit this kind of access
Query tasks assigned to you or sent by you. Filter by status and role. For incremental polling, pass updated_since (an ISO-8601 timestamp, e.g. a previous result\. It is categorised as a Read tool in the Wmux MCP Server, which means it retrieves data without modifying state.
Register the Wmux MCP server in PolicyLayer and add a rule for a2a_task_query: 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 Wmux. Nothing to install.
a2a_task_query 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 a2a_task_query 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 a2a_task_query. 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.
a2a_task_query is provided by the Wmux MCP server (openwong2kim/wmux). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
a2a_task_query is one line of Wmux's registry record.
The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.
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