Fix broken links from deleted plans

- Remove plan 53 reference from metrics-tradeoffs.md (won't fix)
- Update plan 50 reference in plan 91 to avoid broken link
- Fix line length issue in plan 91

https://claude.ai/code/session_01NzqvY9FmwiSXzyGf6PdVnz

Author: claude

docs/guides/metrics-tradeoffs.md

@@ -20,13 +20,7 @@ This guide compares existing mdsmith rules that touch readability and length wit
 
 ## Planned metrics (not implemented)
 
-| Metric                                                      | Goal                                       | Status  |
-|-------------------------------------------------------------|--------------------------------------------|---------|
-| [Conciseness Scoring](../../plan/53_conciseness-scoring.md) | Flag low information density in paragraphs | Planned |
-
-## What conciseness scoring is trying to measure
-
-Conciseness scoring (plan 53) focuses on information density rather than complexity or structure. It aims to flag paragraphs that are easy to read but say too little with too many words, which can waste tokens and create drift in agentic contexts. A plausible starting point is a heuristic that penalizes filler words, hedging language, and verbose phrases while rewarding content-bearing terms.
+No additional metrics are planned at this time.
 
 ## What token budget awareness is trying to measure
 

plan/91_mds037-skip-generated-sections.md

@@ -10,8 +10,8 @@ summary: >-
 ---
 # MDS037 skips paragraphs inside generated sections
 
-Extends [plan 50](50_redundancy-duplication-detection.md)
-(MDS037 duplicated-content).
+Builds on redundancy detection work to skip paragraphs
+inside generated sections (MDS037 duplicated-content).
 
 ## Goal