copy_file

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

The description states 'fails if destination exists,' which contradicts the idempotentHint: true annotation, as repeated calls with the same parameters lead to different outcomes (fail on second call). This is a clear contradiction, warranting a score of 1.

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?

The description is very concise with two sentences, front-loading the core action. However, it redundantly lists required parameters which are already clear from the schema, slightly reducing efficiency.

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 the presence of an output schema, the description does not need to explain return values. It covers the basic operation and failure condition, but lacks details on success behavior, permissions, or edge cases, making it minimally adequate.

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?

With 0% schema description coverage, the description adds minimal value by merely restating the parameter names and required status. It does not provide format, examples, or constraints beyond what the schema already shows.

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 'Copy a file' with a specific verb and resource. It also specifies the failure condition ('Fails if destination exists'), which distinguishes it from sibling tools like write_file or delete_file.

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 mentions that the tool fails if destination exists, providing a condition for usage. However, it gives no explicit guidance on when to use this tool versus alternatives (e.g., write_file, convert_encoding), leaving the agent to infer context.

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