project_open

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

With no annotations provided, the description carries the full burden, and it does so thoroughly. It discloses that opening destroys previous contents, that a Save-As-No-Data checkpoint is taken if the target exists, and that an environment variable controls external file access—valuable behavioral context beyond the schema.

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 three sentences with no redundancy, front-loading the core action and then efficiently covering side effects, prerequisites, and intended use. Every sentence earns its place, and the structure makes the destructive behavior immediately apparent.

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?

Given only two required parameters, no annotations, and no output schema, the description is remarkably complete: it explains the operation, side effects, return content (checkpoint), prerequisites, and configuration needed for external files. An agent has enough context to select and invoke the tool correctly.

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 100%, so the baseline is 3, but the description adds meaningful context beyond the schema: it explains that opening replaces the target model's contents and clarifies the checkpoint behavior. This additional semantic detail justifies a score above baseline.

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 ('Open') and a specific resource ('.mdl project file') and names the destination ('the named model slot'), making the tool's purpose immediately clear. It also clarifies the destructive nature of the operation and the checkpoint behavior, which distinguishes it from generic file-reading tools.

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 description explicitly says to use this tool 'to restore a project after an IC-CAP restart,' providing a clear use case. It also states prerequisites (file must exist, workspace path policy) but does not explicitly mention when not to use it or name alternative tools, so it stops short of a perfect 5.

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