url_checkLive URL health check: follows the full redirect chain (each hop reported), returns final status, content type, response time, TLS certificate expiry and trust, and access hints (login walls, bot blocks). Fresh at call time - use it to verify links before citing them.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | The URL to check (https). |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With readOnlyHint already in annotations, the description goes well beyond by disclosing the full redirect chain reporting, final status, content type, response time, TLS certificate expiry/trust, access hints, and 'fresh at call time' behavior. This gives the agent a comprehensive picture of what the tool does and what to expect.
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 two sentences, leading with the core function and then listing specific outputs and a use case. Every word adds value, and it is perfectly sized for the tool's simplicity.
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 tool with no output schema and read-only annotations, the description fully covers the return values, behavioral nuances, and use context. It is self-contained and leaves no significant gap for an agent to invoke it 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 already provides a complete description for the single URL parameter ('The URL to check (https)'). The tool description adds no additional parameter meaning, only clarifying the overall behavior, so the baseline score of 3 is appropriate given 100% schema 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 clearly identifies the tool as a live URL health check, listing specific outputs (redirect chain, status, content type, response time, TLS details, access hints) that distinguish it from sibling tools like request_tool. The phrase 'verify links before citing them' further clarifies its specific purpose.
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 states a clear use case ('use it to verify links before citing them'), providing context for when to apply the tool. However, it does not explicitly mention when not to use it or compare it to alternatives such as request_tool, so it falls short of a perfect score.
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 has a unique, clearly defined purpose (counters, cron, DNS, email, fixtures, webhooks, KV, locks, name checks, regex, timers, timezone, URL checks). There is no functional overlap; even closely related tools like timer_schedule and cron_next are clearly separated by descriptions.
The dominant naming pattern is <resource>_<action> (e.g., inbox_create, kv_get, lock_acquire, tz_convert). A few tools deviate, such as counter_next and cron_next (resource_qualifier), fixture_rows (resource_noun), and request_tool (verb_noun), but these are minor and do not obscure the overall pattern.
At 24 tools, the server exceeds the typical 3-15 range, leaning heavy. The tools cover many independent utility categories, each with a minimal set of operations, but the overall count feels slightly excessive for a single server, though it is justified by the broad scope.
The server provides complete lifecycles for its functional areas: KV (set/get/list/delete), inbox (create/poll/delete), locks (acquire/release), timers (schedule/status/cancel/verify). Each utility is self-contained, and the request_tool offers a path for extending the surface. No obvious gaps or dead ends within the intended domain.