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

With no annotations, the description carries the full behavioral burden, and it only partially does so: it discloses that the call is a mutation gated by confirmation and that created sessions become bookable by members. It omits permissions/roles required, what happens on scheduling conflicts, timezone defaults, and idempotency. The confirm-gate detail is also duplicated in the schema, so its marginal value is limited.

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 short sentences, mutation nature front-loaded, no filler or repetition. It is efficient, though the extreme brevity borders on under-specification rather than tight editing.

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 an 11-parameter, 6-required mutation with no annotations and no output schema, the description omits auth requirements, the recurring-schedule model (how weekdays/startTime/timezone interact), and any parameter guidance. It is not complete enough for an agent to call this correctly without reading the schema carefully.

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 description coverage is only 36% across 11 parameters, so the description is expected to compensate for undocumented fields (title, capacity, organizationId, durationMinutes, locationId, instructorCoachId) but explains none of them. It adds no syntax, format, or default information beyond what the schema already states.

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 (create a recurring gym class) and adds a scope qualifier ('recurring') that separates it from one-off session creation. It does not, however, contrast itself with nearby siblings like update_gym_class or deactivate_gym_class, so the agent must infer the boundary.

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?

There is no when-to-use guidance, no prerequisites (e.g., an existing organization, location, or coach), and no named alternative for modifying or canceling an existing class. The only usage-adjacent signal is the parenthetical 'confirm-gated', which is not framed as a workflow instruction.

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