mv

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

With no annotations, the description carries full burden. It discloses important behaviors: moving descendants, auto-creating parent directories, and specific error conditions (ENOENT, EEXIST, EINVAL). It does not mention permissions or side effects, but covers mutation and edge cases well.

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 sentences efficiently convey purpose, key behaviors, and error conditions. Front-loaded with the core action, no unnecessary words.

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?

Given no output schema and no annotations, the description covers usage, behavior, and errors thoroughly. It lacks explicit mention of return value, but that is typical for file operations. Overall, it provides sufficient context 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 descriptions cover all 3 parameters (100% coverage), so baseline is 3. The tool description adds value by linking parameters to behaviors (auto-create for destination, error conditions for source and destination) and clarifying store semantics.

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 'Move or rename a file or directory' using a specific verb and resource. It adds key behavior like moving all descendants and auto-creating parent directories, which distinguishes it from siblings like rm, mkdir, and write.

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 implies usage when moving or renaming files/directories, but does not explicitly state when to choose this tool over alternatives or mention exclusions. Sibling tools have different purposes, so the context is adequate but not explicit.

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