apply a map to a surface shader using its original size and tiling

Hi, I'm trying to get a texture that is used as a map in a surface shader. I want the texture to use its original size, and tile when necesarry, but I'm not able to. The texture always upscales to have the size of the object. What should I do? This is the code of the shader:

             sampler2D _MainTex;
         sampler2D _NoiseTex;
         struct Input
         {
             float2 uv_MainTex : TEXCOORD0;
             float2 uv2_NoiseTex : TEXCOORD1;
             fixed4 color;
             float4 screenPos;
             float3 worldPos;
         };
 
 
         void vert(inout appdata_full v, out Input o)
         {
             #if defined( PIXELSNAP_ON )
                 v.vertex = UnityPixelSnap(v_.vertex);
             #endif
 
                 UNITY_INITIALIZE_OUTPUT(Input, o);
                 o.color = v.color * _Color;
 
                 o.worldPos = mul(_Object2World, v.vertex);
         }

             ....

           fixed3 glitt(SurfaceOutput o, Input i)
     {
         float scale = 0.1f;

         fixed4 tex2d = tex2D(_ColdTex, i.uv_MainTex);

         float4 noisetex2d = tex2D(_NoiseTex, i.uv2_NoiseTex);

There, noisetex2d will appear in the scene upscaling the texture to the object, which is bigger than the texture.

Thanks for the help.