context-optimization

Reduce active-session context bloat without losing decisions, errors, evidence, or verification state. Use when tool output is verbose, a long task is.

SKILL.md

GitHub

Context Optimization

Preserve task quality first. Optimize what is loaded and repeated; do not hide diagnostic evidence or install invisible interceptors by default.

1. Diagnose the source

Classify the dominant pressure:

  • repeated instructions or duplicate skill metadata;
  • long command, test, build, or search output;
  • large files read in full instead of targeted excerpts;
  • stale exploration that no longer affects the plan;
  • repeated summaries with no new information;
  • missing checkpoint, causing the same facts to be rediscovered.

Use context-budget for a corpus-wide inventory. Continue here for active-task reduction.

2. Reduce input before output

  • Search first, then read only relevant ranges.
  • Use file lists, counts, hashes, and structured summaries before opening full bodies.
  • Batch independent lookups when the host supports it.
  • Prefer machine-readable filters and selectors over dumping complete datasets.
  • Load detailed references only when their branch of the task is active.

3. Control command output safely

  • Prefer concise or quiet flags only when they preserve errors and exit status.
  • During diagnosis, keep the first failing trace; shorten repeated successful output afterward.
  • Capture large raw output in a file when authorized, then report counts, failures, and representative excerpts.
  • Do not redirect stderr or suppress warnings that may explain a failure.
  • Paginate or cap listings and state that output was truncated.

4. Create a loss-aware checkpoint

Before compaction, handoff, or a long phase transition, record:

  1. objective and acceptance criteria;
  2. decisions and why they were made;
  3. verified facts with source paths or links;
  4. changes already made and tests run;
  5. unresolved risks, failed attempts, and blockers;
  6. exact next actions;
  7. user preferences and prohibitions that still apply.

Keep raw evidence reachable by path instead of copying it into every summary.

5. Compress by relevance

Retain:

  • safety and authorization boundaries;
  • current plan and state;
  • exact errors still under investigation;
  • interfaces, schemas, invariants, and acceptance tests;
  • provenance and uncertainty.

Summarize or drop:

  • superseded hypotheses;
  • repeated successful logs;
  • boilerplate already available in a referenced file;
  • duplicated source excerpts;
  • exploration that cannot affect remaining decisions.

6. Verify after optimization

Check that the checkpoint can answer:

  • What is being done and why?
  • What has already changed?
  • What evidence supports the current direction?
  • What must not be changed or forgotten?
  • What remains and how will completion be verified?

If any answer is missing, restore it before continuing.

Guardrails

  • Do not claim a hidden global hook exists.
  • Do not install command proxies, modify runtime hooks, or intercept all commands without explicit authorization and verified host support.
  • Do not hardcode a context-window size, provider, or model family.
  • Do not trade debuggability for fewer tokens.
  • Do not rewrite user-owned files merely to save session context.