Initiate a trust handshake with a peer agent. Creates a cryptographic challenge, records the handshake, and returns a signed token the peer can verify. Args: peer_did: The DID of the peer agent to handshake with. capabilities: List of capability strings requested for this session.
AI agents invoke establish_handshake to trigger actions in Agentos. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
This tool triggers an external operation (cryptographic handshake initiation) with a peer agent, creates and records state (the handshake record and signed token), and establishes a trust relationship. It is not a simple read, and its effects (trust establishment, capability grants for a session) are external and operational.
From the tool's definition Initiate a trust handshake with a peer agent. Creates a cryptographic challenge, records the handshake, and returns a signed token the peer can verify.
Documented attack patterns abuse exactly the kind of access establish_handshake gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Agentos, and nothing reaches the server without passing your rules. This is the rule we recommend for establish_handshake:
{
"version": "1",
"default": "deny",
"tools": {
"establish_handshake": {
"limits": [
{
"counter": "establish_handshake_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}establish_handshake stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
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Initiate a trust handshake with a peer agent. Creates a cryptographic challenge, records the handshake, and returns a signed token the peer can verify. Args: peer_did: The DID of the peer agent to handshake with. capabilities: List of capability strings requested for this session. It is categorised as a Execute tool in the Agentos MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Agentos MCP server in PolicyLayer and add a rule for establish_handshake: 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 Agentos. Nothing to install.
establish_handshake is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the establish_handshake 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 establish_handshake. 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.
establish_handshake is provided by the Agentos MCP server (@microsoft/agentos-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Agentos, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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18 Agentos tools catalogued and risk-classified — across an index of 43,000+ MCP servers.