Fix db_execute_query parameters input type

internal/tiger/mcp/db_tools.go

@@ -18,12 +18,12 @@ import (
 
 // DBExecuteQueryInput represents input for tiger_db_execute_query
 type DBExecuteQueryInput struct {
-	ServiceID      string `json:"service_id"`
-	Query          string `json:"query"`
-	Parameters     []any  `json:"parameters,omitempty"`
-	TimeoutSeconds int    `json:"timeout_seconds,omitempty"`
-	Role           string `json:"role,omitempty"`
-	Pooled         bool   `json:"pooled,omitempty"`
+	ServiceID      string   `json:"service_id"`
+	Query          string   `json:"query"`
+	Parameters     []string `json:"parameters,omitempty"`
+	TimeoutSeconds int      `json:"timeout_seconds,omitempty"`
+	Role           string   `json:"role,omitempty"`
+	Pooled         bool     `json:"pooled,omitempty"`
 }
 
 func (DBExecuteQueryInput) Schema() *jsonschema.Schema {
@@ -36,7 +36,7 @@ func (DBExecuteQueryInput) Schema() *jsonschema.Schema {
 	schema.Properties["query"].Description = "PostgreSQL query to execute"
 
 	schema.Properties["parameters"].Description = "Query parameters for parameterized queries. Values are substituted for $1, $2, etc. placeholders in the query."
-	schema.Properties["parameters"].Examples = []any{[]any{1, "alice"}, []any{"2024-01-01", 100}}
+	schema.Properties["parameters"].Examples = []any{[]string{"1", "alice"}, []string{"2024-01-01", "100"}}
 
 	schema.Properties["timeout_seconds"].Description = "Query timeout in seconds"
 	schema.Properties["timeout_seconds"].Minimum = util.Ptr(0.0)
@@ -166,7 +166,7 @@ func (s *Server) handleDBExecuteQuery(ctx context.Context, req *mcp.CallToolRequ
 
 	// Execute query and measure time
 	startTime := time.Now()
-	rows, err := conn.Query(queryCtx, input.Query, input.Parameters...)
+	rows, err := conn.Query(queryCtx, input.Query, util.ConvertSliceToAny(input.Parameters)...)
 	if err != nil {
 		return nil, DBExecuteQueryOutput{}, fmt.Errorf("query execution failed: %w", err)
 	}

internal/tiger/util/convert.go

@@ -47,3 +47,18 @@ func ConvertStringSlicePtr[T ~string](ss []string) *[]T {
 	}
 	return &out
 }
+
+// ConvertSliceToAny converts a slice of some type to slice of any.
+// Returns nil if the input slice is nil.
+func ConvertSliceToAny[T any](ts []T) []any {
+	if ts == nil {
+		return nil
+	}
+
+	out := make([]any, len(ts))
+	for i, t := range ts {
+		out[i] = any(t)
+	}
+	return out
+
+}