copy_file

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

With annotations present (readOnlyHint=false, destructiveHint=false), the description adds value by disclosing the configuration requirement and clarifying behavior when dst is a directory. It does not mention overwrite behavior details, but annotations already signal non-read-only and non-destructive, so this is acceptable.

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 two sentences long, front-loaded with the core action, and every sentence provides relevant information without fluff.

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?

The tool has no output schema and the description does not mention what happens on success, errors, or the default overwrite behavior when dst exists. Given the low complexity and good annotations, this is a clear gap but not severe.

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 coverage is 100%, so parameters are documented. The description adds extra meaning for dst by explaining that if it's a directory, the source filename is preserved, which goes beyond the schema's simple type/description.

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 the tool's action ('Copy a file to a new location') with the resource (file). It distinguishes from sibling tools like move_file by explicitly using 'copy' rather than 'move', and from write_file by implying an existing source.

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 gives useful context about destination behavior and a prerequisite (allow_file_write), but it does not explicitly mention when to prefer this tool over alternatives like move_file. The usage context is implied rather than explicitly contrasted.

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