layerfs_workspace_mount

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

Annotations (readOnly=false, destructive=false, openWorld=true, idempotent=false) already flag this as a mutating, side-effecting call, and the description adds real substance beyond that: it discloses that LayerFS may create a Sandbox, that a {sandbox,path} handle is returned, and that the image is a local immutable sha256 digest. It stops short of describing lifecycle obligations (unmount/commit) or failure behavior, so not a 5.

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?

Three tight sentences, front-loaded with the core action, then side-effect, then return-handle guidance. No filler, though the phrase 'Save the returned {sandbox,path} handle' is slightly terse and assumes the reader knows what the handle is used for.

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 no output schema, the description does the minimum by naming the return shape ({sandbox,path}). For a stateful mount tool, though, it omits lifecycle context an agent needs — whether an unmount is required, what happens to the sandbox on failure, and whether the mount is scoped to a session.

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 compensate. It does explain that 'image' is a local immutable sha256 digest, adding meaning beyond the regex pattern, and 'Mount a branch' implies branch identifies the branch to mount. However neither parameter's accepted values or constraints are spelled out, leaving a partial gap.

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 (Mount) plus resource (a branch) and the resulting object (isolated writable FUSE Workspace), which cleanly separates it from siblings like layerfs_workspace_unmount, layerfs_workspace_commit and layerfs_workspace_exec. An agent knows exactly what this tool produces without opening the schema.

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?

Usage is implied rather than stated: mounting is clearly the prerequisite step before exec/fs operations, and 'Save the returned {sandbox,path} handle' hints at follow-on calls. But it never explicitly says when to prefer this over alternatives or what prerequisites (branch must exist, etc.) are required.

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