manage-context-size

Managing Context Size

This skill teaches you how to avoid context exhaustion when working with large Terra datasets, scattered workflows, and verbose Cromwell metadata.

Context Size Risks

These operations can exhaust your context window:

Operation	Risk Level	Potential Size
get_job_metadata (full)	CRITICAL	100K+ tokens per workflow
get_workflow_logs with many shards	HIGH	25K+ tokens per task log
get_entities for large tables	HIGH	10K+ tokens for 100 entities
get_submission_status with include_inputs=True	MEDIUM	30K+ tokens for 9 workflows

Safe Patterns

1. Always Use Summary Mode for Metadata

# SAFE: Returns ~1-2K tokens
get_job_metadata(workspace_namespace, workspace_name, submission_id, workflow_id)

# DANGEROUS: Can return 100K+ tokens
# (There is no "full" mode - the tool protects you)

Summary mode is the default. It returns structured, actionable information without the verbose raw metadata.

2. Get Log URLs Before Fetching Content

For scattered workflows (50+ shards), fetching all logs can quickly exhaust context.

# Step 1: Get URLs only (fast, small response)
get_workflow_logs(
    workspace_namespace, workspace_name, submission_id, workflow_id,
    fetch_content=False  # Default
)

# Step 2: Identify which specific tasks failed
get_job_metadata(..., mode="summary")

# Step 3: Fetch content only for failed tasks you need
# (Consider fetching logs one at a time for scattered workflows)

3. Check Table Sizes Before Fetching Entities

# Step 1: Check row counts
get_workspace_data_tables(workspace_namespace, workspace_name)
# Response: {"tables": [{"name": "sample", "count": 5000}, ...]}

# Step 2: If count > 100, reconsider whether you need all entities
# Often, specific entity names from workflow inputs are sufficient

4. Limit Workflow Count in Submission Status

# Default: Returns first 10 workflows (manageable)
get_submission_status(workspace_namespace, workspace_name, submission_id)

# For large submissions, the default limit protects you
# Only use max_workflows=0 if you truly need all workflow details