design_create_practice_session

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

With no annotations, the description carries the full burden of explaining behavior. It does disclose a key side effect ('Creates both a timer layer and a skeleton layer'), which is useful, but it omits whether this requires an open sketch, whether existing layers are overwritten, and what is returned.

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 short sentences and front-loads the primary action. The second sentence adds a relevant behavioral detail, though it could be slightly more integrated rather than a separate 'Creates…' clause.

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 five-parameter creation tool with nested objects, no annotations, and no output schema, the description is minimally adequate. It explains the layer side effect but does not address prerequisites, return values, or interaction with existing sketches, which would help an agent invoke it confidently.

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 100%, so the schema already documents all five parameters, including the enum for `type` and the nested `tags` object. The description adds no extra parameter semantics such as how `seed` interacts with `tags` or how `duration` and `poseCount` override session type defaults.

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 states a specific verb and resource: 'Create a timed pose practice session.' It distinguishes itself somewhat from siblings like design_add_pose_skeleton or design_advance_pose by emphasizing a 'practice session' rather than a single layer or pose operation, though it doesn't explicitly name an alternative.

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 guidance on when to use this tool versus alternatives such as design_add_pose_skeleton, design_advance_pose, or design_randomize_pose. The agent must infer usage context solely from the phrase 'timed pose practice session.'

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