open_in_finder

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

With no annotations, the description carries full burden. It discloses the platform requirement and mentions the action (reveal in Finder). It does not detail the exact behavior (e.g., opening Finder and selecting the file) or potential outcomes if the file is missing, but for a simple reveal operation this is adequate.

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 sentences long, no extraneous words, and front-loads the action. Every sentence contributes meaningful information.

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 reveal tool with no output schema, the description covers the main purpose and a critical constraint. It does not mention return behavior (e.g., whether it returns a success message), but this is minor given the tool's simplicity. The sibling tool list includes related tools, providing context.

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 schema already documents both parameters. The description echoes the purpose but adds no new semantic detail beyond what the schema provides. Baseline score of 3 is appropriate.

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 clearly states the tool reveals a document in macOS Finder using either document_id or file_path. It specifies the platform and a key constraint (same Mac). This distinguishes it from siblings like 'open_document_external' and 'reveal_mail_in_finder'.

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 provides a clear context: it works only when the app and MCP client are on the same Mac. However, it does not explicitly state when to use this tool versus alternatives, such as when to use 'open_document_external' instead.

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