fix(tools): exempt MCP discovery tools from agent allowlists

pkg/tools/search_tool.go

@@ -14,6 +14,8 @@ import (
 
 const (
 	MaxRegexPatternLength = 200
+	RegexSearchToolName   = "tool_search_tool_regex"
+	BM25SearchToolName    = "tool_search_tool_bm25"
 )
 
 type RegexSearchTool struct {
@@ -27,7 +29,7 @@ func NewRegexSearchTool(r *ToolRegistry, ttl int, maxSearchResults int) *RegexSe
 }
 
 func (t *RegexSearchTool) Name() string {
-	return "tool_search_tool_regex"
+	return RegexSearchToolName
 }
 
 func (t *RegexSearchTool) Description() string {
@@ -96,7 +98,7 @@ func NewBM25SearchTool(r *ToolRegistry, ttl int, maxSearchResults int) *BM25Sear
 }
 
 func (t *BM25SearchTool) Name() string {
-	return "tool_search_tool_bm25"
+	return BM25SearchToolName
 }
 
 func (t *BM25SearchTool) Description() string {
@@ -294,6 +296,15 @@ func (t *BM25SearchTool) getOrBuildEngine() *bm25CachedEngine {
 	return cached
 }
 
+func isToolDiscoveryToolName(name string) bool {
+	switch strings.ToLower(strings.TrimSpace(name)) {
+	case BM25SearchToolName, RegexSearchToolName:
+		return true
+	default:
+		return false
+	}
+}
+
 // SearchBM25 ranks hidden tools against query using BM25 via utils.BM25Engine.
 // This non-cached variant rebuilds the engine on every call. Used by tests
 // and any code that doesn't hold a BM25SearchTool instance.