Sheet Data Enrichment & Summarization#

Workflow#

Phase 1: Reconnaissance#

1. Read the full sheet (or specify range) to understand the schema
2. Identify the source column (e.g., URLs/links) and target column (data to fill)
3. Count empty rows in the target column — these are the work items
4. Confirm the plan with the user before proceeding

Phase 2: Extraction#

Process rows in batches. For each row with an empty target column:

1. Classify the source before fetching:
   • Regular article URL → web_fetch
   • SPA / JS-rendered page → browser automation
   • WeChat article (mp.weixin.qq.com) → browser (captcha may block web_fetch)
   • Social media (Weibo, Douyin, etc.) → browser or note as "no extractable data"
   • Dead link / paywall → flag for user
2. Extract the target data from the fetched content:
   • Search for the data in multiple locations (top, bottom, metadata)
   • Use targeted patterns (see references/extraction-patterns.md)
   • If ambiguous, flag for manual review rather than guessing
3. Verify before writing (每篇先核实):
   • Confirm the extracted value is correct before writing to the sheet
   • Cross-reference with known mappings if available
   • When batch-processing, verify a sample first, then apply patterns

Phase 3: Write-back#

1. Write confirmed values to the target column
2. Always verify row alignment — read the row before writing to confirm the target cell matches the expected entry
3. Use single-cell writes ( G5:G5) not bare references ( G5)
4. For Feishu Sheets: range format must be sheetId!G5:G5

Phase 4: Summarization#

When the user requests aggregation:

1. Re-read all enriched sheets to capture any manual corrections
2. Group by the requested dimensions (e.g., assignee → contributor → sum)
3. Sort groups by total descending for readability
4. Output to a new sheet/spreadsheet with headers + subtotals + grand total

Key Lessons (Extraction)#

Where to find data on a web page#

Data placement varies by source. Always check multiple locations:

PositionExampleBelow title作者：张三 / By Jane DoeEnd of article（记者 李四） / Reporter: JohnBefore timestamp王五 2026-03-18 14:00Metadata line文｜赵六 / Author: SarahCombined format采写：记者 孙七 编辑：周八

Never conclude "no data" after checking only the top of the page. Always check the end too.

When to use browser vs web_fetch#

SignalToolStatic HTML, server-renderedweb_fetch (fast, cheap)Returns empty/minimal contentSwitch to browserURL contains mp.weixin.qq.comBrowser (WeChat captcha)SPA framework (React/Vue/Angular)BrowserBaidu mini-program ( smartapps.cn)Browser or find alternate URLSocial media embeds (Weibo, Douyin)Browser, but often no structured data

Reusable mappings#

When the same source consistently maps to the same value across rows/sheets:

1. Build a mapping table after confirming 2+ instances
2. Apply mappings to future rows without re-fetching
3. Always note the mapping source for audit

Common "no data" patterns#

These formats typically have no individual attribution:

• Flash news / wire alerts (e.g., "财联社电", "每经AI快讯")
• Press releases / corporate announcements
• Social media reposts without original attribution
• Aggregated roundup articles

Mark these clearly (leave blank or use a placeholder like "/" per user preference).

Row Alignment Safety#

Critical: Off-by-one errors are the #1 failure mode when writing to spreadsheets.

Before every write:

1. Read the target row to verify the adjacent cells match expectations
2. If processing multiple rows, re-read periodically to catch drift
3. Never assume row N in your data maps to row N in the sheet — always verify

Feishu Sheets Specifics#

• Range format: sheetId!A1:B2 (not sheet name)
• Single-cell write: sheetId!G5:G5 (not sheetId!G5)
• Get sheet IDs via feishu_sheet action info
• Write returns revision number — useful for tracking changes
• Cannot create new sheet tabs in existing spreadsheet via API; create a new spreadsheet for summaries

Output Format#

Summary sheets should include:

• Headers: Group dimension, detail dimension, count, total
• Subtotals: Per group
• Grand total: Final row
• Sorting: By total descending within each group, groups ordered by subtotal descending