Check whether a domain or IP is listed on the major DNS blocklists (DNSBLs) that mail providers consult before accepting mail — the usual reason legitimate mail silently lands in spam. Returns each zone checked, whether it is listed, and the return code. Deterministic DNS lookups, no LLM.
| Name | Required | Description | Default |
|---|---|---|---|
| domain | Yes | A public domain or IP address, e.g. example.com or 203.0.113.10 |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare readOnlyHint=true, and the description adds valuable context beyond that: it mentions deterministic DNS lookups, no LLM involvement, and what the return contains (each zone checked, listed status, return code). This exceeds the baseline for annotation-covered tools, though it does not disclose potential network latency or zone variations.
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?
The description is compact and well-structured, with two sentences that front-load the core purpose. Every clause earns its place: the why, the what, and the output are all clearly conveyed without redundancy.
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?
The tool is simple with one parameter and no output schema, but the description compensates by explicitly stating return values (zones checked, listed status, return codes) and the deterministic nature of lookups. It is complete enough for an AI agent to invoke correctly, though a list of specific DNSBL zones might have added further clarity.
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 100% for the single 'domain' parameter, which already explains it accepts a public domain or IP address. The description reinforces that the parameter is used for DNSBL lookup but provides no additional syntax or formatting details beyond the schema, matching the baseline for high coverage.
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 uses a specific verb and resource: 'Check whether a domain or IP is listed on the major DNS blocklists (DNSBLs)' – clearly stating the tool's function and scope. It also distinguishes this from sibling tools like check_domain_health or check_broken_links by focusing specifically on email blacklists and spam delivery.
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 provides clear context for when to use the tool by noting it addresses the 'usual reason legitimate mail silently lands in spam.' However, it does not explicitly mention when not to use it or name alternative tools for broader domain health checks, so it falls short of a full 5.
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 resource and action. The five check tools are differentiated by their target (agent readiness, broken links, domain health, email blacklist, MCP health), and asset/alert management tools have clear CRUD/lifecycle boundaries. No two tools appear to overlap.
All 16 tools follow a consistent verb_noun pattern with lowercase and underscores (e.g., check_domain_health, create_asset, list_my_alerts). The verbs are clear and consistently used, making the API predictable.
16 tools is well-scoped for a monitoring service that spans asset management, alert lifecycle, multiple diagnostic checks, vendor status, and plan listing. Every tool has a distinct role and earns its place without redundancy.
The tool surface covers full asset CRUD (create, list, update, delete, get checks), alert lifecycle (list, acknowledge, resolve), and a broad set of standalone checks. Minor gaps like a direct 'get asset' endpoint or manual re-check are absent, but core workflows are fully supported.
