finder_rename_file

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

Annotations already declare non-read-only, idempotent, non-destructive behavior, so the bar is lower, yet the description still adds real value: it discloses the authorized-roots boundary and the refuse-on-overwrite rule, which explains a non-obvious failure the annotations do not cover. It omits cross-volume/atomicity behavior and the human-approval path implied by _approvalId.

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 short sentences with the operational constraints front-loaded and no padding. The trailing '[v1.0.0; permissions: none]' metadata is low-value noise for selection purposes, keeping it out of the top score.

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 annotations plus 100% schema coverage carry most of the burden. The description adds the two things an agent most needs here, the authorized-roots boundary and the no-overwrite rule, so it is nearly complete for a simple rename operation.

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% and all four parameters are documented in the schema, including the required _idempotencyKey and optional _approvalId. The description only restates that destination is an absolute path, which the schema already says, so baseline 3 applies.

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 (rename) and resource (file) plus a scope constraint (inside authorized roots) and a behavioral guarantee (refuse overwrite). It does not explicitly differentiate itself from the sibling finder_move_file, which is the closest alternative an agent would consider, so it falls short of a 5.

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 'inside authorized roots' clause implies a precondition and 'refuse overwrite' implies a failure mode, which gives some implicit guidance. However, it never states when to pick this over finder_move_file or finder_copy_file, nor what to do when the destination already exists, so usage must be inferred.

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