Three tools with complete input schemas and descriptions, but significant gaps in output documentation and error handling. Tool names follow verb_noun pattern (relay_create, relay_send, relay_heartbeat). Descriptions are present (60-120 chars) but lack actionable recovery guidance. Parameters have types and descriptions, but no enums for constrained values (e.g., 'status' accepts 'active'|'composing'|'idle' but not declared as enum). No documented output schemas. Error handling exists in _handle_http_error() but responses are generic ('Not your turn') without recovery steps. Session state management via .agent-relay.json is undocumented in tool descriptions.

• Add explicit output schemas to all three tools. Document relay_create returns {relay_id: string, agent_names: [string], token?: string}; relay_send returns {message_id: integer, relay_id: string, version: integer}; relay_heartbeat returns {status: string, relay_id: string}.
• Convert 'status' and 'type' parameters to enum constraints in JSON Schema. E.g., 'status': {type: 'string', enum: ['active', 'composing', 'idle'], default: 'active}.
• Enhance error messages with recovery steps. E.g., 'Not your turn. Call relay_status to check whose turn it is, then retry relay_send when it's your turn.'
• Document session state behavior in relay_send and relay_heartbeat descriptions. Add: 'Parameters default to session values from the last relay_create call, persisted in .agent-relay.json. Provide explicit values to override.'
• Add idempotency support documentation. relay_send accepts 'idempotency_key' but no description explains how retries work or when to reuse the key.