Auth Status

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

With no annotations, the description carries the full disclosure burden and does so well: it states that only metadata is returned, token values are never exposed, and it defines the agent's expected action when no usable session exists. This covers safety, output scope, and failure handling.

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 compact and front-loaded: the first sentence states the core purpose, and the following sentences add only high-value behavioral and remediation details. Every sentence earns its place.

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 status-check tool with an output schema available, the description fully covers what the agent needs: purpose, return scope, token safety, and user-facing recovery instructions. No critical context is missing.

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 tool has zero parameters, so parameter documentation is unnecessary. Baseline 4 applies because there is nothing for the description to add beyond the already-complete empty schema.

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 starts with a specific verb and resource: 'Report whether a saved Anytime Fitness session exists and still refreshes.' This clearly differentiates it from data-query siblings like occupancy, forecast, nearby_clubs, and visits, which return domain data rather than session state.

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 clear operational context: when this tool or any other call reports no usable session, the agent should direct the user to run `af-gym login --phone <number>`. It does not explicitly list when-not-to-use alternatives, but the zero-parameter auth-check role is unambiguous.

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