dns_tlsOpen a TLS handshake on :443, capture the presented cert + protocol version + cipher, and grade the result A-F. Surfaces days-until-expiry, SAN list, self-signed detection, and findings like 'CBC-mode cipher in use'.
| Name | Required | Description | Default |
|---|---|---|---|
| port | No | ||
| domain | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, openWorld, and non-destructive behavior. The description adds valuable behavioral detail beyond annotations: that it actively initiates a network handshake and grades the result, plus what findings it surfaces. This helps the agent understand the real-world side effect despite readOnlyHint.
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 concise, front-loaded sentences with no filler. The first sentence states the core operation and outputs, the second lists key surfaces. 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?
With no output schema, the description explains the main returned fields (expiry, SAN, self-signed, findings, grade). Annotations cover safety, and the input schema covers the port range and default. It is complete enough for selection and basic invocation, though parameter semantics could be stronger.
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?
Schema description coverage is 0%, so the description bears the burden of explaining parameters. It mentions ':443' but does not clarify that 'port' is an overridable parameter or describe that 'domain' is the target hostname. The only parameter it implicitly addresses is the default port, leaving the required domain parameter essentially unexplained.
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 ('Open a TLS handshake'), the resource (port 443), and the specific data captured (cert, protocol version, cipher, A-F grade, expiry, SAN, self-signed detection). This clearly distinguishes it from sibling tools like dns_lookup or dns_certificates, which are not live handshakes.
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 conveys that this is a live, active check by explicitly saying 'Open a TLS handshake on :443', implying it is for current TLS posture rather than historical or registry-based DNS data. It does not name alternatives or exclusions, but the live-handshake framing provides clear context for when to use it.
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.
Multiple tools have genuinely blurry boundaries: company_change vs company_changes differ only by singular/plural yet serve different purposes, company_domain vs company_classify vs company_lookup_auto all accept a domain, geo_zip_lookup vs geo_enrich vs geo_zip_batch all return ZIP profiles, and email_validate subsumes much of email_disposable and email_free_provider. The domain prefixes help narrow search space, but within many domains an agent cannot reliably predict which tool is the right one.
All 129 tools uniformly follow a snake_case [domain]_[topic] convention (company_, fx_, geo_, dns_, weather_, tax_), which is highly predictable and consistent. Minor deviations include the confusing company_change/company_changes pair, and inconsistent suffix usage (_batch appears on address_validate_batch, company_domains_batch, geo_zip_batch but not on equivalent lookup tools elsewhere).
129 tools far exceeds the 50+ extreem-mismatch threshold, bundling roughly 28 unrelated data domains (weather, fx, tax, ccompany, dns, jobs, flight, email, phone, tax...) into a single MCP surface. Even focusing on one domain forces the agent to load an enormous unrelated tool list; this should be split into many smaller domain-specific servers.
Per-domain coverage is impressively thorough: weather spans current/forecast/hourly/historical/normals/marine/route/air-quality, fx covers rates/convert/historical/volatility/correlation/strenth, and company includes lookup/enrichment/networks/timeline/peer-comparison plus six buyer-tuned signals with profile-introspection tools. Minor gaps like flight being historical-only and smtp probes skipping major email providers are documented scope decisions rather than dead ends.