oaslananka/a2amesh/a2a-mcp-consumption

A2A MCP Consumption

Use this skill to connect an MCP-capable client to the published a2amesh-mcp server and invoke only its reviewed A2A tool surface.

When to use

Use this skill when the user asks to:

• connect a local MCP client to A2A Mesh through stdio or loopback Streamable HTTP;
• discover the bounded MCP tool set;
• diagnose MCP connection or tool-registration failures; or
• invoke a2a_discover, a2a_send_message, or a2a_get_task under the documented policy.

This is not an OpenClaw-specific plugin and does not make any client part of the A2A protocol implementation.

Required context

Confirm:

• the exact released @a2amesh/mcp version or reviewed local build;
• the transport: stdio or loopback Streamable HTTP;
• the exact tool allowlist and whether it remains read-only;
• expected tenant, audience, scopes, and approval identifiers;
• named credential variables already provided by the runtime secret source;
• statically allowlisted A2A agents and destinations; and
• the requested read-only or state-changing tool invocation.

Workflow

1. Start from .mcp.json or the matching Codex, VS Code, or OpenCode example.
2. Prefer stdio for a local one-user flow. Use Streamable HTTP only on loopback with the documented bearer credential.
3. Keep the default allowlist at a2a_discover,a2a_get_task until a send is explicitly approved.
4. Run the client's status, doctor, or probe command before any tool call.
5. Start with a2a_discover for the expected tenant.
6. Use a2a_get_task only for a known allowlisted agent and task.
7. Before a2a_send_message, obtain explicit approval, add the send scope and tool, set a fresh scoped approval identifier, and restart the MCP process.
8. Preserve audit evidence and report bounded reason codes without exposing input or output secrets.

Safety boundaries

• Fail closed on tool, tenant, audience, scope, approval, agent, and destination mismatch.
• Keep SSRF and outbound-network restrictions enabled.
• Never expose terminal, credential, merge, publish, deployment, or destructive tools through this bridge.
• Do not place concrete credentials in plugin files, client configuration committed to Git, logs, audit payloads, or chat output.
• Treat MCP annotations as hints; server authorization and audit policy remain authoritative.
• Bound timeout, cancellation, response size, and task artifact output.
• Do not claim generic MCP or A2A conformance from one client probe.

Failure modes

Stop and report the bounded reason code when:

• the MCP server cannot start or the client cannot negotiate the transport;
• a requested tool is outside the allowlist;
• tenant, audience, scope, or approval checks fail;
• an agent is unavailable or its destination violates outbound policy;
• the operation times out or is canceled;
• audit emission fails; or
• returned content cannot be safely redacted.

Output format

Return:

• Client and transport context
• Registered tool allowlist
• Tenant, audience, scope, and approval posture
• Probe or doctor evidence
• Tool invocation result
• Audit evidence pointers
• Failure reason codes
• Redaction and privacy notes
• Safe rollback step