Definition
Plain language
A safety layer that rewrites tool instructions to spell out the rules and edge cases upfront.
As stated in the literature
In Life-Harness, the layer that augments tool descriptions with explicit precondition and edge-case clarifications to reduce contract-violation failures.
Why it matters: Many agent failures come from vague tool docs, and spelling out the contract up front prevents a class of avoidable mistakes without retraining the model.
For example, before an agent sees a 'send_email' tool description, the layer appends notes like 'recipient must be a verified address' and 'attachments over 25MB will fail silently.'
Heard on the show
“An Environment Contract Layer that rewrites tool descriptions to spell out the edge cases upfront — the cancellation-only-works-on-undeparted-flights kind of clarification.”Episode 071 — When the Model Is Fine and the Plumbing Is Broken: Fixing Agents at the Interface