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

Annotations only declare readOnlyHint=false, so the description carries the rest and usefully discloses the confirm-gate dry-run behavior — a trait the agent cannot infer elsewhere. It omits downstream effects (roster/attendance history, reversibility), which keeps it below a 5.

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 compact clauses with zero filler, and the confirm-gate caveat is front-loaded so the agent knows about the preview behavior before calling.

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 mutation tool with no output schema and thin annotations, the core behavior is covered, but enrollment prerequisites, whether attendance records are affected, and the preview response shape are all left unstated.

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 33%; only 'confirm' is documented in the schema. The description implicitly maps 'member' to userId and 'one class session' to sessionId but adds no format or constraint detail for those required parameters, so it only partially compensates for the gap.

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 and resource ('Remove a member from one class session'), which an agent can clearly separate from add_member_to_gym_class_session and cancel_gym_class_session. It stops short of naming those siblings, so differentiation is implied rather than explicit.

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 phrase 'from one class session' hints at the session-scoped vs standing-scoped distinction, but the description never says when to use this instead of cancel_gym_class_standing or remove_client. No prerequisites or exclusions are given.

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