Discover subdomains of a domain from public Certificate Transparency logs (crt.sh). Useful for mapping a company's public surface (app., api., staging., etc.). Best-effort: crt.sh can be slow; returns a note if unavailable.
| Name | Required | Description | Default |
|---|---|---|---|
| domain | Yes | Registrable domain, e.g. stripe.com |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full responsibility. It discloses best-effort behavior, potential slowness of crt.sh, and a fallback note if unavailable. It could add more details about return structure, but the key operational caveats are covered.
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?
Three concise sentences: purpose, use case, and caveat. Every sentence adds value and the main action is front-loaded with no filler.
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 single-parameter, read-only tool without an output schema, the description covers purpose, source, use case, and failure mode. It does not explicitly state the return format, but 'Discover subdomains' strongly implies a list and the operational note covers error behavior.
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 only parameter 'domain' has a complete schema description ('Registrable domain, e.g. stripe.com'), and the tool description adds no additional semantic meaning beyond that. With 100% schema coverage, baseline 3 is appropriate.
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?
States a specific action ('Discover subdomains') and a distinct resource ('public Certificate Transparency logs (crt.sh)'). This is precise enough to distinguish it from sibling tools like dns_lookup or tech_stack, even without naming them explicitly.
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?
Provides a clear use case ('mapping a company's public surface') with examples of subdomain patterns. It does not list exclusions or name alternatives, so it lacks explicit 'when not to use' guidance.
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.
Each tool targets a distinct intelligence area—DNS, registration, email, subdomains, tech stack—so the set is largely unambiguous. The composite domain_report intentionally overlaps with several other tools, which creates minor selection ambiguity, though its description makes the combined-purpose clear.
All tool names follow a consistent pattern: lowercase snake_case noun phrases describing the data or intelligence returned (dns_lookup, domain_intel, domain_report, email_deliverability, subdomains, tech_stack). This is a predictable and uniform convention.
Six tools is well-scoped for a domain and company intelligence server. Each tool covers a distinct reconnaissance area, and the composite domain_report justifies its place without bloating the tool surface.
The server covers the main domain-intelligence lifecycle: DNS, registration, subdomains, email authentication, and technology fingerprinting. Minor gaps exist, such as no direct company-name-to-domain lookup and limited DNS record types, but agents can work around these for most lead-qualification and recon workflows.