replace_lines_code

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

With no annotations, the description carries the burden of behavioral disclosure. It does disclose that replacement requires an exact originalCode match and that the file must already exist. However, it omits permissions, side effects, failure modes, and return behavior, leaving important gaps for a mutation tool.

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 one concise, front-loaded sentence with no filler. It communicates the core purpose efficiently, though for a 5-parameter mutation tool it may be slightly under-specified. Every word earns its place.

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?

This tool has 5 required parameters, no output schema, and no annotations, yet the description provides only a one-line purpose. It lacks usage context, behavioral details, and outcome expectations, making it insufficient for an agent to use confidently in a complex editing scenario.

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 input schema covers 100% of parameters with descriptions, so the baseline is 3. The description adds a little context by highlighting 'exact content validation' for originalCode and 'specific lines' for the line range, but it does not expand on syntax, formatting, or edge cases 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 uses a specific verb and resource: 'Replace specific lines in existing files.' The phrase 'exact content validation' adds a distinguishing feature. It is clear, though it does not explicitly differentiate from sibling tools like find_and_replace_code or insert_lines_code.

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 no guidance on when to use this tool versus alternatives such as insert_lines_code, delete_lines_code, or find_and_replace_code. The intended use case is implied but not stated, and no exclusions or alternative recommendations are provided.

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