GSC Drops — Ranking Drop Detection

@skills/seo/references/mcp-degradation.md @skills/seo/references/gsc-api-reference.md

Identifies pages and keywords that lost clicks between the last 28 days and the prior 28-day period. Sorts by biggest losses first. Highlights CRITICAL drops (>50% loss).

MCP Check

Before calling any GSC tool, verify the MCP is connected:

1. Use ToolSearch with query

   +google-search-console

2. If tools returned — note the actual tool name prefix, proceed to Inputs
3. If no tools returned — display the GSC MCP error template from

   references/mcp-degradation.md

   and stop:

## Google Search Console MCP Not Available

The `/seo gsc drops` command requires the GSC MCP, which is not currently connected.

**What you can do:**
- Use `/seo technical <url>` for crawlability and indexability analysis (no live data)
- Use `/seo audit <url>` for a full static SEO audit

**To connect GSC MCP:**
- Install and configure a Google Search Console MCP server (see README for setup)
- Add it to ~/.claude/mcp.json at user scope (NOT project scope)
- Verify GSC property access before running commands (domain vs URL prefix format)
- See references/gsc-api-reference.md for property format details

Inputs

• site

  : The GSC property URL. Accept both formats:
  • Domain property:

    sc-domain:example.com

  • URL prefix:

    https://example.com

    or

    https://www.example.com

  • If user provides a bare domain (no prefix), call

    list_sites

    to identify the correct property format registered in GSC.

Date Calculation

Use Bash to calculate the two comparison periods (GSC has ~3 day delay):

currentEnd=$(date -v-3d +%Y-%m-%d)
currentStart=$(date -v-31d +%Y-%m-%d)
previousEnd=$(date -v-31d +%Y-%m-%d)
previousStart=$(date -v-59d +%Y-%m-%d)
echo "Current: $currentStart to $currentEnd | Previous: $previousStart to $previousEnd"

Execution

Step 1 — Page-level comparison: Call

compare_performance

with:

• siteUrl

  : the site property

• currentStartDate

  : currentStart

• currentEndDate

  : currentEnd

• previousStartDate

  : previousStart

• previousEndDate

  : previousEnd

• dimension

  :

  "page"

• limit

  : 500

Step 2 — Query-level comparison: Call

compare_performance

with the same date params but:

• dimension

  :

  "query"

• limit

  : 500

Post-processing:

• Filter Step 1 results to rows where

  clicksChange < 0

  (pages that lost clicks)
• Filter Step 2 results to rows where

  clicksChange < 0

  (queries that lost clicks)
• Sort both lists by

  clicksChange

  ascending (biggest losses first)
• For each row, calculate change percentage if not provided:

  changePercent = (clicksChange / previousClicks) * 100

• Mark rows with

  changePercent < -50

  as CRITICAL

Output Format

## GSC Drops: [site property]
**Current Period:** [currentStart] to [currentEnd]
**Previous Period:** [previousStart] to [previousEnd]

### Top Dropping Pages
| Page URL | Current Clicks | Previous Clicks | Change | Change% | Severity |
|----------|---------------|-----------------|--------|---------|----------|
| [url] | [n] | [n] | [n] | [X.X%] | CRITICAL / — |
...

### Top Dropping Queries
| Query | Current Clicks | Previous Clicks | Change | Change% | Severity |
|-------|---------------|-----------------|--------|---------|----------|
| [query] | [n] | [n] | [n] | [X.X%] | CRITICAL / — |
...

**Note:** CRITICAL = more than 50% drop in clicks between periods.

Show top 25 dropping pages and top 25 dropping queries. Truncate long URLs to 60 characters with

...

for readability. If no drops detected, report: "No pages or queries lost clicks between the two periods."