feat: add marketing tools registry for agent discovery

Create centralized tools/ directory with REGISTRY.md index and 29
integration guides covering analytics, SEO, CRM, payments, referral,
email, ads, automation, and commerce platforms.

Each guide includes API endpoints, authentication, common operations,
and links to relevant skills. Updated AGENTS.md and key skills
(referral-program, analytics-tracking, email-sequence, paid-ads)
with tool integration references.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tools/integrations/linkedin-ads.md

@@ -0,0 +1,164 @@
+# LinkedIn Ads
+
+B2B advertising platform with professional targeting.
+
+## Capabilities
+
+| Integration | Available | Notes |
+|-------------|-----------|-------|
+| API | ✓ | Marketing API for campaigns, audiences, analytics |
+| MCP | - | Not available |
+| CLI | - | Not available |
+| SDK | - | API-only (community libraries available) |
+
+## Authentication
+
+- **Type**: OAuth 2.0
+- **Header**: `Authorization: Bearer {access_token}`
+- **Scopes**: `r_ads`, `r_ads_reporting`, `rw_ads`
+
+## Common Agent Operations
+
+### Get ad accounts
+
+```bash
+GET https://api.linkedin.com/v2/adAccountsV2?q=search
+
+Authorization: Bearer {access_token}
+```
+
+### Get campaigns
+
+```bash
+GET https://api.linkedin.com/v2/adCampaignsV2?q=search&search.account.values[0]=urn:li:sponsoredAccount:{account_id}
+
+Authorization: Bearer {access_token}
+```
+
+### Get campaign analytics
+
+```bash
+GET https://api.linkedin.com/v2/adAnalyticsV2?q=analytics&pivot=CAMPAIGN&dateRange.start.year=2024&dateRange.start.month=1&dateRange.start.day=1&dateRange.end.year=2024&dateRange.end.month=1&dateRange.end.day=31&campaigns=urn:li:sponsoredCampaign:{campaign_id}&fields=impressions,clicks,costInLocalCurrency,conversions
+
+Authorization: Bearer {access_token}
+```
+
+### Create campaign
+
+```bash
+POST https://api.linkedin.com/v2/adCampaignsV2
+
+Authorization: Bearer {access_token}
+
+{
+  "account": "urn:li:sponsoredAccount:{account_id}",
+  "name": "Campaign Name",
+  "type": "SPONSORED_UPDATES",
+  "costType": "CPC",
+  "unitCost": {
+    "amount": "5.00",
+    "currencyCode": "USD"
+  },
+  "dailyBudget": {
+    "amount": "100.00",
+    "currencyCode": "USD"
+  },
+  "status": "PAUSED"
+}
+```
+
+### Update campaign status
+
+```bash
+POST https://api.linkedin.com/v2/adCampaignsV2/{campaign_id}
+
+Authorization: Bearer {access_token}
+
+{
+  "patch": {
+    "$set": {
+      "status": "ACTIVE"
+    }
+  }
+}
+```
+
+### Get creatives
+
+```bash
+GET https://api.linkedin.com/v2/adCreativesV2?q=search&search.campaign.values[0]=urn:li:sponsoredCampaign:{campaign_id}
+
+Authorization: Bearer {access_token}
+```
+
+### Get audience counts
+
+```bash
+POST https://api.linkedin.com/v2/audienceCountsV2
+
+{
+  "audienceCriteria": {
+    "include": {
+      "and": [{
+        "or": {
+          "urn:li:adTargetingFacet:titles": ["urn:li:title:123"]
+        }
+      }]
+    }
+  }
+}
+```
+
+## Key Metrics
+
+| Metric | Description |
+|--------|-------------|
+| `impressions` | Ad impressions |
+| `clicks` | Total clicks |
+| `costInLocalCurrency` | Spend |
+| `conversions` | Conversion count |
+| `leadGenerationMailContactInfoShares` | Lead form submissions |
+
+## Campaign Types
+
+- `SPONSORED_UPDATES` - Sponsored content
+- `TEXT_AD` - Text ads
+- `SPONSORED_INMAILS` - Message ads
+- `DYNAMIC` - Dynamic ads
+
+## Targeting Options
+
+### Job-Based
+- Job titles
+- Job functions
+- Seniority levels
+- Years of experience
+
+### Company-Based
+- Company names
+- Industries
+- Company size
+- Company followers
+
+### Professional
+- Skills
+- Groups
+- Schools
+- Degrees
+
+## When to Use
+
+- B2B advertising
+- Job title targeting
+- Account-based marketing
+- Lead generation campaigns
+
+## Rate Limits
+
+- 100 requests/day (basic)
+- 10,000 requests/day (Marketing Developer Platform)
+
+## Relevant Skills
+
+- paid-ads
+- analytics-tracking