open_file

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 only restates the core action and reveals nothing about edge cases — e.g., what happens if the path does not exist (error vs. new-file creation), whether VSCode receives focus, or whether this replaces the current editor tab. These are material behaviors left undisclosed.

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 a single tight sentence with no wasted words, appropriate for a simple two-parameter tool. It is slightly minimal — a short supporting clause distinguishing editor-open from explorer-reveal would strengthen it — but nothing present is redundant.

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 tool whose schema fully documents both parameters, the description covers the core operation adequately. However, it omits edge-case behavior (nonexistent path), any output/return information (no output schema exists), and sibling-tool relationships, leaving moderate gaps for an agent deciding between open_file and explorer-focused siblings.

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% — both 'path' and 'line' already have clear descriptions in the schema. The tool description adds no parameter-level detail beyond what the schema provides, which matches the baseline of 3 for high schema coverage.

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 ('a file in VSCode'), clearly conveying the core action. It can be distinguished from siblings like create_file (creation vs opening), run_terminal_command (files vs commands), and search_workspace, though it does not explicitly differentiate from reveal_in_explorer / select_file_in_explorer, which also deal with showing files.

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?

No guidance is given on when to use this tool versus alternatives. The description does not distinguish opening a file in the editor from revealing/selecting it in the explorer, nor does it mention any exclusions or conditions. An agent would have to infer usage purely from the tool name.

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