Single tool 'webhookvty_scan' has a reasonable description (127 chars, within 10-1024 range) but critical schema deficiencies. Input schema is present but minimal: only 'target' parameter with basic string type and description. No output schema documented anywhere, LLMs cannot infer what fields to expect from the JSON response. Parameter lacks constraints (min/max length, format, path validation rules). Tool name 'webhookvty_scan' is verb-noun but generic; 'scan' alone doesn't convey the specific domain (webhook verification). No error handling guidance, no pagination support, no per-item success/failure reporting. The description mentions 'Stripe/Adyen/PayPal/Plaid' but doesn't explain when to use this tool vs. other security scanners, or what 'findings' structure contains. Baseline: 100% of A+ tools document return types; this tool does not.

• Document the output schema in the tool description or as a separate schema field. Example: 'Returns {tool: string, findings: [{id: string, sev: string, where: string}], score: number}'. This lets LLMs know what fields to extract.
• Add constraints to the 'target' parameter: 'Absolute or relative filesystem path to scan. Must be a readable directory. Max 1000 files scanned per call.'
• Expand the description to explain domain and use case: 'Audits payment webhook handler code (Stripe/Adyen/PayPal/Plaid) for signature verification bugs, idempotency issues, and replay-attack vulnerabilities. Call this before deploying webhook handlers to production.'
• Add error handling examples: 'If target is not found, returns {findings: [], error: "Path not found"}. If scan times out, returns {findings: [], error: "Scan exceeded 30s timeout, target may be too large"}.'
• Rename tool to 'audit_payment_webhooks' or 'verify_webhook_signatures' to clarify the specific action and domain, reducing LLM confusion with generic scanners.