finder_open_file

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

Annotations already declare readOnlyHint=false, destructiveHint=false and idempotentHint=true, so the safety profile is covered. The description adds the scoping constraint that only files under user-authorized roots can be opened and notes 'permissions: none', which is useful, but it omits the human-approval flow implied by the _approvalId parameter and any side effect of launching an external app.

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?

A single front-loaded sentence with no wasted prose. The bracketed '[v1.0.0; permissions: none]' tag is metadata noise that slightly dilutes an otherwise tight statement.

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?

With an output schema present, return values need not be explained, and the annotations carry the safety profile. The remaining gap is that the description never surfaces the approval/idempotency mechanics of a side-effecting open action, but it is adequate for correct invocation.

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 path, _approvalId and _idempotencyKey are fully documented in the schema. The description adds only the 'authorized file' notion, which overlaps the path description already in the schema; baseline 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?

States a specific verb (open) and resource (authorized file) plus the mechanism (default app), which implicitly separates it from finder_read_file (reads contents) and system_open_app (launches an app). It does not explicitly name those siblings, so differentiation is inferable rather than stated.

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?

There is no when-to-use guidance, no exclusions, and no alternatives named. The word 'authorized' hints at a precondition but the description never says when to choose this over finder_read_file or system_open_app.

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