fix: address PR review feedback for MCP tools support

- Avoid logging sensitive cfg.Args in ConnectServer; log args_count instead
- Sanitize server/tool name components in MCPTool.Name() to ensure valid
  identifiers for downstream providers (lowercase, [a-z0-9_-] only)
- Add slack as 5th MCP server example in config.example.json
- Move Dockerfile.full and docker-compose.full.yml into docker/ directory
  for consistency with existing docker/Dockerfile and docker/docker-compose.yml
- Fix all Makefile docker-* targets to reference correct compose file paths
- Fix docker/docker-compose.full.yml build context (.. ) and volume paths
- Fix scripts/test-docker-mcp.sh compose file path and replace cowsay test
  with actual @modelcontextprotocol/server-filesystem MCP server test

pkg/tools/mcp_tool.go

@@ -35,10 +35,67 @@ func NewMCPTool(manager MCPManager, serverName string, tool *mcp.Tool) *MCPTool
 	}
 }
 
+// sanitizeIdentifierComponent normalizes a string so it can be safely used
+// as part of a tool/function identifier for downstream providers.
+// It:
+//   - lowercases the string
+//   - replaces any character not in [a-z0-9_-] with '_'
+//   - collapses multiple consecutive '_' into a single '_'
+//   - trims leading/trailing '_'
+//   - falls back to "unnamed" if the result is empty
+//   - truncates overly long components to a reasonable length
+func sanitizeIdentifierComponent(s string) string {
+	const maxLen = 64
+
+	s = strings.ToLower(s)
+	var b strings.Builder
+	b.Grow(len(s))
+
+	prevUnderscore := false
+	for _, r := range s {
+		isAllowed := (r >= 'a' && r <= 'z') ||
+			(r >= '0' && r <= '9') ||
+			r == '_' || r == '-'
+
+		if !isAllowed {
+			// Normalize any disallowed character to '_'
+			if !prevUnderscore {
+				b.WriteRune('_')
+				prevUnderscore = true
+			}
+			continue
+		}
+
+		if r == '_' {
+			if prevUnderscore {
+				continue
+			}
+			prevUnderscore = true
+		} else {
+			prevUnderscore = false
+		}
+
+		b.WriteRune(r)
+	}
+
+	result := strings.Trim(b.String(), "_")
+	if result == "" {
+		result = "unnamed"
+	}
+
+	if len(result) > maxLen {
+		result = result[:maxLen]
+	}
+
+	return result
+}
+
 // Name returns the tool name, prefixed with the server name
 func (t *MCPTool) Name() string {
-	// Prefix with server name to avoid conflicts
-	return fmt.Sprintf("mcp_%s_%s", t.serverName, t.tool.Name)
+	// Prefix with server name to avoid conflicts, and sanitize components
+	sanitizedServer := sanitizeIdentifierComponent(t.serverName)
+	sanitizedTool := sanitizeIdentifierComponent(t.tool.Name)
+	return fmt.Sprintf("mcp_%s_%s", sanitizedServer, sanitizedTool)
 }
 
 // Description returns the tool description