layerfs_fs_cp

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

Annotations already declare readOnly=false, idempotent=false, destructive=false, and openWorld=true. The description adds the important non-schema constraint that the destination is exact and must not exist, but leaves out permission requirements, whether source directories are copied recursively, and what 'checkpoint' entails. With annotations covering the safety profile, this is a moderate addition.

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, front-loaded with the core action, and no filler. Every sentence contributes a purpose or constraint.

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 4-parameter mutation with no output schema and zero schema descriptions, the definition is too sparse: it does not explain 'message', the checkpoint result, recursive/directory behavior, or possible failure modes. Annotations help with safety hints but cannot fill those functional gaps.

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 0%, so the description must carry parameter meaning. It implies from/to are paths and branch selects a branch, and clarifies that 'to' must not exist, but it never explains the optional 'message' parameter or the required 'from'/'to' distinction beyond destination exactness.

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 names a concrete verb ('Copy') and resource ('a path on a branch') and mentions checkpointing, so the action is identifiable. It does not explicitly distinguish this from layerfs_fs_mv or fs_apply, but the core purpose is clear enough to act on.

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 gives a destination constraint ('must not exist') but no when-to-use guidance, no alternatives such as layerfs_fs_mv, and no prerequisites or conditions. An agent must infer when copy is preferred over move or write.

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