[Web] Liveness/latency pre-flight for a URL: is it up, HTTP status and class, response latency in ms, whether it redirects and where, content-type and server. Costs $0.001. Use before relying on a dependency.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations, so description carries full burden. Describes all key behavioral outputs (status, latency, redirects, content-type, server). No mention of side effects, which is appropriate for a read-only check tool. Cost of $0.001 disclosed.
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 zero waste. First sentence lists capabilities compactly, second sentence adds cost and usage guidance. Perfectly front-loaded.
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?
Simple tool with one parameter; description adequately covers output behavior (status, latency, redirects, etc.) despite lacking output schema. Could mention timeout behavior or error handling, but sufficient for typical use.
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?
Only one parameter (url) with 0% schema description coverage. Description merely repeats 'URL' without adding format constraints (e.g., http/https required). Schema is minimal, description should compensate with more detail like length or protocol requirements.
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?
Description clearly states the tool checks URL liveness/latency, lists returned data (HTTP status, latency, redirects, etc.). Differentiates from sibling web tools like unshorten_url or web_extract by focusing on pre-flight health 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?
Explicitly says 'Use before relying on a dependency', providing clear usage context. Could mention alternatives but the pre-flight purpose is well understood. Cost info adds practical 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.