copy_code

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

With no annotations, the description must disclose behavior. It mentions the 1-based line numbering, default for end_line, and include_line_numbers option, and implies a read-only copy via the verb 'copy.' However, it does not explicitly state side effects (e.g., no modification to source), behavior on out-of-bounds lines, or error handling.

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 concise and well-structured with a purpose sentence followed by Args and Returns sections. Every sentence provides useful information, with no unnecessary filler.

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 description covers the operation, parameters, and return type, and an output schema exists. It is adequate for a simple read-only tool, though it misses edge-case details and doesn't relate to sibling tools. Overall, it is sufficiently complete for most use cases.

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?

The schema has no property descriptions (0% coverage), but the tool description compensates fully by explaining each parameter: source_file path, start_line 1-based, end_line defaults to start_line, and include_line_numbers as a flag. This adds meaningful semantics beyond the schema.

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 explicitly states 'Copy code lines from source file,' which clearly identifies the action (copy) and resource (source file). The Args section with start_line and end_line clarifies that it copies a specific line range, distinguishing it from sibling copy_entire_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 provides no when-to-use guidance, no prerequisites, and no references to alternative tools like copy_entire_file. It only describes the function, leaving the agent to infer when this tool is appropriate.

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