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

Annotations already mark this as read-only and non-destructive. The description adds valuable traits beyond that: it is a public endpoint requiring no keychers, uses GET, and reports billing state plus runner_ready. This gives the agent a meaningful behavioral profile beyond the structured 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 a single compact sentence that front-loads the most important fact: this is a public readiness check. Every segment earns its place: endpoint, response fields, and authentication requirement.

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 parameterless health-check tool, the description is complete. It specifies the HTTP method, endpoint, public authentication status, and the key response fields (billing and runner_ready), so an agent has everything needed to invoke and interpret the call.

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?

There are zero parameters, so there is nothing for the description to explain. The baseline of 4 applies because the tool needs no input configuration and the schema fully reflects that.

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 names the exact resource and verb: 'GET /health', and defines the tool's purpose as a public readiness check. The 'No key' qualifier distinguishes it from sibling tools that likely require authentication, and the listed response fields clarify its scope.

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?

'Public readiness' plus 'No key' gives a clear context for when to call this tool: basic health checks without authentication. It does not explicitly compare against alternatives like smoke, so it misses the top score for explicit when-not/alternative routing, but the guidance is not merely implied.

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