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

With no annotations, the description carries the full burden. It usefully discloses that the operation is confirm-gated (preview when confirm=false) and that booked members are affected, which is genuine consequence information. It does not state permissions required, whether cancellation is reversible, or whether members are notified.

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?

Two tight sentences with no filler, and the confirm-gating constraint is front-loaded ahead of the member-impact warning. Efficient for the information it delivers.

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 3-parameter destructive mutation with no annotations and no output schema, the description covers the gating and the member impact but leaves out permissions, reversibility, and the outcome for booked members beyond 'affected'.

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?

Schema coverage is only 33%, with just the confirm parameter documented. The description hints that identifying the correct session matters ('confirm which session first') but adds no format or meaning for sessionId or reason, so it fails to compensate for the undocumented parameters.

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?

States a specific verb+resource: 'Cancel one dated class session', and the word 'session' (vs. sibling cancel_gym_class / deactivate_gym_class) signals a scoped, dated instance rather than the whole class. It does not explicitly name those siblings, so differentiation is implied rather than stated.

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?

'confirm-gated' and 'confirm which session first' give some usage-relevant context about the two-step flow, but there is no explicit guidance on when to use this versus cancel_session, deactivate_gym_class, or reschedule_session.

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