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

Annotations already indicate read-only, idempotent, non-destructive behavior. The description adds valuable detail: the 'ready' flag behavior after restart and the 503 response for paid endpoints until ready. It also confirms the cost (free). This goes beyond annotations and helps agents understand operational implications.

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 concise sentences, front-loaded with the key message 'Free. Liveness and store readiness.' Every sentence adds essential information: the HTTP status meaning, the ready flag, and the effect on paid endpoints. No word is wasted.

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 zero-parameter health check, the description is largely complete. It explains the return status, the ready field, and the impact on paid endpoints. However, it does not detail the exact response body structure (e.g., fields beyond 'ready'), but given the simplicity and lack of an output schema, this is acceptable. The information provided is sufficient for an agent to use the tool 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?

With zero parameters, the baseline is 4. There is nothing for the description to clarify about parameters since the schema is empty. The description correctly focuses on behavior instead, and no additional parameter semantics are needed.

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 states the tool's purpose: 'Liveness and store readiness.' It explains that it returns 200 when the server is up, distinguishing it from the many data-providing sibling tools. The verb is implied (check), but the resource and behavior are unambiguous.

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 useful context: it is free and tells agents that paid endpoints answer 503 until the store is ready. This implies using this health check before calling paid endpoints, though it does not explicitly say 'use this to check readiness before other tools.' It gives sufficient guidance within the context of sibling tools.

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