Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond the idempotent, read-only, and open-world annotations, the description reveals that any HTTP response below 500 is considered up, and redirects are reported but not followed. No contradiction with annotations.

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 front-loaded with the core purpose and returns, followed by behavioral details, sibling guidance, and cost. Slightly verbose due to the cost note, but well-organized and informative.

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?

Given the tool's simplicity (one parameter, clear annotations, and an output schema), the description fully covers what the tool does, what it returns, its behavior, and when to use it. Cost note adds extra context.

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 single parameter 'url' is already well-described in the schema (100% coverage). The description adds little new information beyond the schema, but confirms it expects a public HTTP(S) URL. 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?

The description clearly identifies it as a liveness ping tool for any public URL, specifying the return values (up/down, HTTP status, latency) and distinguishing itself from siblings like get_uptime and get_uptime_report.

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 states when to use this tool (high-frequency monitoring loops) and when to use alternatives (for redirect following, headers, full timing/TLS/CDN reports). Also mentions cost per call.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.