Open file or folder

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does mention that it uses the default Windows handler and that Explorer is used for folders, which is useful. However, it doesn't describe potential side effects like window focus changes, or whether it returns success/failure, or what happens if the path doesn't exist. It's adequate but not rich for a tool with zero annotation support.

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 tightly packed sentences with the core action and handler front-loaded, followed by a useful list of friendly names. Every word earns its place, and there is no redundancy or fluff.

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 simple one-parameter open command with no output schema and no annotations, the description covers purpose, input semantics, and the default handler. It doesn't mention error handling or return values, but these are arguably not critical for this operation. The description is essentially complete for the tool's complexity.

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 schema description covers the `path` parameter fully, including both absolute/relative paths and friendly names. Since schema coverage is 100%, the baseline is 3. The description adds no additional parameter semantics beyond restating the friendly names, so it doesn't exceed the 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 resource ('file or folder'), and clarifies it uses the default Windows handler (Explorer for folders). This clearly differentiates it from siblings like `open_path_with` and `open_app`, so an agent can distinguish without inspecting other 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?

It clearly explains the tool's behavior (default handler) and the acceptable inputs (paths and friendly names). While it doesn't explicitly say 'use this instead of open_path_with', the contrast is implicit—this uses default handler, the sibling presumably uses a specific application. This is clear context but lacks explicit exclusion or alternative selection criteria.

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