open_model

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

No annotations are supplied, so the description carries the full burden, and it does disclose the key side effect: a workspace is opened in the user's browser, with four linked views. It also discloses the read-back behavior ('describe the current model'). It omits edge cases such as behavior when a model is already open or no model exists, 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 sentences, both earning their place: the first establishes what opens and what the user sees, the second delivers the critical ordering constraint. The sequencing instruction is placed last where it is most likely to be read as the call condition.

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 session-initialization tool with no output schema, the description supplies enough to act: what opens, where, and its prerequisite status. The remaining gap is that it does not say what the returned 'description of the current model' contains or what happens on failure, which is minor given there is no output schema to lean on.

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 takes zero parameters, so the baseline is 4 and there is nothing further the description needs to disambiguate. The description correctly implies a no-argument invocation by describing it as an unconditional session-opening step.

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?

Uses a specific verb+resource pairing ('Open the SketchFlow 3D workspace') and clarifies the resource with concrete detail (parametric solids in four linked views). It also states the secondary effect ('describe the current model'), so an agent knows both actions performed, and the model_* naming makes the sibling boundary obvious.

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?

Explicitly states ordering: 'Call this before the other model_* tools,' which tells the agent exactly when it belongs in a sequence and implicitly names the dependent sibling set. It stops short of stating when NOT to call it (e.g. if a workspace is already open), so it is strong but not fully exhaustive.

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