# Feature Specification: Palo Alto SSH Query Tool

**Feature Branch**: `001-paloalto-ssh-tool`
**Created**: 2026-01-30
**Status**: Draft
**Input**: User description: "MCP server with read-only tools for network equipment. Initial tool for PA-5250 (Palo Alto) devices via SSH to retrieve firewall configuration."

## User Scenarios & Testing *(mandatory)*

### User Story 1 - Query Firewall Configuration (Priority: P1)

As a network administrator using an LLM agent, I want to retrieve firewall configuration
information from Palo Alto devices (any model running PAN-OS) so that I can analyze security
policies, troubleshoot issues, and audit configurations without directly accessing the device CLI.

**Why this priority**: This is the core functionality of the tool. Without the ability to query
firewall configuration, the MCP server provides no value. This represents the minimum viable
product.

**Independent Test**: Can be fully tested by connecting to a Palo Alto device and executing a
read-only show command (e.g., `show system info`). Delivers immediate value by returning
structured device information.

**Acceptance Scenarios**:

1. **Given** valid device credentials and a reachable Palo Alto device, **When** the user requests
   system information via the MCP tool, **Then** the tool returns structured device information
   including hostname, software version, and uptime.

2. **Given** valid device credentials and a reachable Palo Alto device, **When** the user requests
   security policy information, **Then** the tool returns the current security rules in a
   structured format.

3. **Given** valid device credentials and a reachable Palo Alto device, **When** the user executes
   a read-only command, **Then** the response is returned within 30 seconds.

---

### User Story 2 - Handle Connection Failures Gracefully (Priority: P2)

As a network administrator using an LLM agent, I want clear error messages when connection to a
device fails so that I can quickly identify and resolve connectivity issues.

**Why this priority**: Error handling is essential for usability. Users need to understand why a
query failed to take corrective action. This is critical but secondary to core query functionality.

**Independent Test**: Can be tested by attempting to connect to an unreachable device or using
invalid credentials. Delivers value by providing actionable error messages.

**Acceptance Scenarios**:

1. **Given** invalid credentials for a Palo Alto device, **When** the user attempts to execute a
   command, **Then** the tool returns a clear authentication error message without exposing
   sensitive details.

2. **Given** an unreachable device (network timeout), **When** the user attempts to connect,
   **Then** the tool returns an error indicating the device is unreachable within the timeout
   period.

3. **Given** a device that refuses the SSH connection, **When** the user attempts to connect,
   **Then** the tool returns an error indicating the connection was refused.

---

### User Story 3 - Execute Multiple Commands (Priority: P3)

As a network administrator using an LLM agent, I want to execute multiple read-only commands in
a single session so that I can gather comprehensive configuration data efficiently without
repeated connection overhead.

**Why this priority**: While single-command queries provide value, batch queries improve
efficiency for comprehensive audits. This builds upon the core functionality.

**Independent Test**: Can be tested by submitting multiple commands in one request and verifying
all results are returned in a single structured response.

**Acceptance Scenarios**:

1. **Given** valid credentials and a list of 3 read-only commands, **When** the user submits the
   batch request, **Then** all command outputs are returned in a single structured response with
   each result labeled.

2. **Given** a batch request where one command fails, **When** the tool executes the batch,
   **Then** successful command results are still returned along with error details for the failed
   command.

---

### Edge Cases

- What happens when the SSH session is interrupted mid-command? The tool returns a partial result
  indicator with whatever output was received and an error flag.

- What happens when the user provides an empty or malformed command? The tool validates input
  before attempting connection and returns a validation error.

- What happens when the device returns unexpected output format? The tool returns the raw output
  with a warning that parsing may be incomplete.

- What happens when connection times out after partial authentication? The tool returns a timeout
  error with details about the connection stage reached.

- What happens when the user attempts a write/modify command? The device rejects the command due
  to insufficient account permissions and returns a permission denied error.

## Requirements *(mandatory)*

### Functional Requirements

- **FR-001**: System MUST expose a Palo Alto query tool via the MCP protocol interface.

- **FR-002**: System MUST accept connection parameters including device hostname/IP and port
  per request. Credentials (username/password) MUST be configured via environment variables
  in mcp.json, NOT passed as tool parameters.

- **FR-003**: System MUST establish SSH connections to any Palo Alto device running PAN-OS and
  execute provided commands.

- **FR-004**: System MUST return command output in structured JSON format including the command
  executed, raw output, and parsed fields where applicable.

- **FR-005**: System MUST document in the MCP tool definition that all operations are read-only.
  Read-only enforcement is delegated to the device-level account permissions.

- **FR-006**: System MUST return descriptive error messages for connection failures, authentication
  failures, timeout conditions, and invalid commands without exposing sensitive information.

- **FR-007**: System MUST support execution of multiple commands in a single request with
  aggregated results.

- **FR-008**: System MUST implement connection timeout handling with a configurable timeout
  value (default: 30 seconds).

- **FR-009**: System MUST NOT store or log authentication credentials beyond the scope of a
  single request.

- **FR-010**: System MUST skip SSH host key verification and accept any host key. This enables
  maximum flexibility in dynamic network environments where device IPs may change frequently.

### Key Entities

- **Device Connection**: Represents connection parameters for a Palo Alto device including
  hostname/IP and port (default: 22). Credentials are separate (from environment variables).

- **Query Request**: Represents a user request containing target device connection info and one
  or more commands to execute. Includes optional timeout override.

- **Query Response**: Represents the result of a query including execution status, command
  output(s), any errors encountered, and execution metadata (timestamps, duration).

- **Command**: Represents a single CLI command with validation status (allowed/rejected) and
  categorization (system info, security policy, interface config, etc.).

## Success Criteria *(mandatory)*

### Measurable Outcomes

- **SC-001**: Users can retrieve firewall system information from a Palo Alto device in under
  30 seconds from request to response.

- **SC-002**: 95% of valid queries to reachable devices with correct credentials succeed on
  first attempt.

- **SC-003**: Error messages enable users to identify the root cause of connection failures
  without additional troubleshooting in 90% of cases.

- **SC-004**: Users can execute a batch of up to 10 commands in a single request without
  performance degradation beyond linear scaling.

- **SC-005**: Configuration modifications are impossible due to read-only account permissions
  on target devices (device-level enforcement).

## Assumptions

- SSH is the standard and supported protocol for Palo Alto device management access.
- All Palo Alto devices running PAN-OS use the same CLI command syntax.
- Users have valid SSH credentials with read-only permissions on target devices (account-level
  enforcement ensures no configuration modifications are possible).
- Network connectivity between the MCP server and target devices is the user's responsibility.
- Connection timeout default of 30 seconds is reasonable for typical network latency conditions.

## Clarifications

### Session 2026-01-30

- Q: SSH authentication method? → A: Password authentication only (no SSH key support)
- Q: Device model scope? → A: Any Palo Alto device running PAN-OS (not limited to PA-5250)
- Q: Credential management? → A: Via environment variables in mcp.json (not tool parameters)
