Address second round of PR review feedback

- revise-for-readability: drop "estimated" from the quality-checklist metric
  source (computed / not measured)
- revise-for-readability: use scalar `input_contract: null` to match the
  convention used by all other no-input templates
- readability-gate: clarify the Output note — do not inject the gate block
  verbatim, but a format MAY populate its own scorecard fields from the metrics

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: abeltrano

protocols/guardrails/readability-gate.md

@@ -190,10 +190,10 @@ Metrics: FRE <value|not measured>, FKGL <value|not measured>,
 Residual issues: <count, or "None">
 ```
 
-Report this to the user (or in the change summary); do NOT inject it into the
-produced artifact. A consuming format MAY fold these metrics into its own
-scorecard section — this keeps consuming formats unchanged and avoids format
-drift.
+Report this block to the user (or in the change summary). Do NOT inject the
+block verbatim into the produced artifact. A consuming format MAY populate its
+own existing scorecard fields from these metrics — that is not injecting the
+block, and it keeps consuming formats unchanged and avoids format drift.
 
 ## Composability
 

templates/revise-for-readability.md

@@ -19,11 +19,7 @@ params:
   document: "The document (or section) to revise — pasted text or a file path"
   target_audience: "Who reads this document (e.g., expert engineers, new team members, general technical audience); sets the readability target band"
   constraints: "Any terms, style rules, or sections that must be preserved verbatim, beyond the default protected tokens"
-input_contract:
-  type: null
-  description: >
-    Any prose document or document section supplied as a parameter — Markdown,
-    plain text, or a file path. No prior pipeline artifact is required.
+input_contract: null
 output_contract:
   type: readability-revision-report
   description: >
@@ -110,7 +106,7 @@ Before finalizing, verify:
 - [ ] The Revised Document section (report Section 1) contains the full revised
       document, usable as-is
 - [ ] Measurement scope lists what was included and excluded, and the metric
-      source (computed / estimated / not measured)
+      source (computed / not measured)
 - [ ] Scorecard shows before and after values for every metric, with target and
       status
 - [ ] Every protected token (normative keywords, identifiers, requirement IDs,