Send a probe request with a foreign Origin header to a URL and report its CORS response headers. Flags wildcard-origin + credentials combinations and arbitrary-origin reflection, both common CORS misconfigurations.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | The URL to probe |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It explicitly discloses that the tool sends an active probe request with a foreign Origin header and inspects response headers, which is the key behavioral trait. It does not mention request method, exact origin value, or whether credentials are included, but the disclosed behavior is sufficient for a focused scanner of this kind.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences with no filler. The action is front-loaded, the resource is named, and the detection targets are given in a compact but informative second sentence. Every clause earns its place.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a one-parameter tool with no output schema, the description covers what it does, how it does it, and what it flags. It does not detail the exact return format, but the phrase 'report its CORS response headers' and 'flags' gives enough context for an agent to select and invoke the tool correctly.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema has 100% coverage for the single 'url' parameter, so the baseline is 3. The description adds context about why the URL is being probed, but it does not add meaning to the parameter itself beyond the schema's 'The URL to probe'.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description states a specific action ('Send a probe request with a foreign Origin header to a URL'), a clear resource ('CORS response headers'), and specific detection outcomes ('wildcard-origin + credentials combinations' and 'arbitrary-origin reflection'). This clearly differentiates it from sibling security tools like security_headers_audit or ai_crawler_policy_check.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description makes the intended usage context clear: it is for probing a URL's CORS behavior and detecting common misconfigurations. It does not explicitly name alternatives or say when not to use it, but the specialized wording provides enough context without being misleading.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Many tools audit overlapping site signals (seo_audit vs structured_data_extract vs tech_stack_fingerprint; page_performance_check vs pagespeed_insights; ssl_cert_check vs ssl_labs_grade; broken_link_check vs sitemap_url_validator), so an agent could initially pick the wrong one. Descriptions usually clarify the distinction, but the boundaries are not always obvious.
Most names follow a snake_case target+operation pattern (ssl_cert_check, email_deliverability_check), but check_open_ports and check_robots_sitemap reverse the order, and the action suffixes vary widely (check, audit, validate, lookup, extract, grade, report, insights). Still readable, but not a single predictable convention.
At 29 tools, the server is above the 25-tool threshold and feels like an undifferentiated grab bag of single-purpose audits rather than a tightly scoped toolkit. Many checks could be consolidated (e.g. the separate SSL and performance tools, or domain_report versus its component checks).
For a web/domain/email/security diagnostics toolbelt, the coverage is unusually broad: DNS, TLS, email, SEO, structured data, vulnerabilities, ports, redirects, and more are all represented. Minor gaps exist (no generic HTTP request/debug tool, no zone-transfer or full WHOIS history), but agents can accomplish most diagnostic workflows without hitting dead ends.