A tool that returns a 400KB page dump poisons every later step. The model pays for it on each turn, and the context fills with text nobody reads.

// config/clutch.php
'spill' => [
    'enabled' => true,
    'threshold_bytes' => 8192,
    'preview_bytes' => 1024,
],

Past the threshold, the full output is written to an artifact and the model gets a bounded preview plus the artifact id, with the truncation stated plainly so it does not answer from the fragment as though it were the whole thing. The full text stays downloadable through the ordinary artifact route.