Show a typing indicator on a received message. Also marks the message as read. Indicator auto-clears after ~25s or when you reply.
AI agents use send_typing_indicator to create or update resources in Mcp Ap2 — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mcp Ap2 environment.
The tool modifies message state (marking as read) and UI state (typing indicator), which are data/state changes. These are reversible and have minimal blast radius. While part of an A2A payment protocol server, this specific tool performs only messaging housekeeping—no financial, destructive, or execute-level operations.
From the tool's definition Tool performs state modifications: 'marks the message as read' (state change) and 'show a typing indicator' (state change on messaging UI). Both are reversible write operations.
Documented attack patterns abuse exactly the kind of access send_typing_indicator gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mcp Ap2, and nothing reaches the server without passing your rules. This is the rule we recommend for send_typing_indicator:
{
"version": "1",
"default": "deny",
"tools": {
"send_typing_indicator": {
"limits": [
{
"counter": "send_typing_indicator_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}send_typing_indicator stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Show a typing indicator on a received message. Also marks the message as read. Indicator auto-clears after ~25s or when you reply. It is categorised as a Write tool in the Mcp Ap2 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Mcp Ap2 MCP server in PolicyLayer and add a rule for send_typing_indicator: 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 Mcp Ap2. Nothing to install.
send_typing_indicator 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 send_typing_indicator 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 send_typing_indicator. 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.
send_typing_indicator is provided by the Mcp Ap2 MCP server (@codespar/mcp-ap2). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Mcp Ap2, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
1300 Mcp Ap2 tools catalogued and risk-classified — across an index of 43,000+ MCP servers.