edit_file

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

Beyond annotations (which provide no safety hints), the description discloses that old_string must be unique and the tool fails if ambiguous, that replace_all changes this, and that allow_file_write permission is required. It stops short of detailing error handling for not-found text or return format.

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?

Four sentences, front-loaded with the action, and every sentence earns its place by conveying usage, requirements, or failure modes. No redundant or fluff content.

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 tool's complexity and the absence of an output schema, the description covers the core editing workflow, prerequisites, and a key failure mode. Minor gaps remain around return values and what happens when old_string is not found, but it's sufficient for typical 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 already covers all four parameters, but the description adds meaningful nuance: 'fails if ambiguous' for old_string and 'By default' for uniqueness behavior. It also reinforces the role of replace_all, adding error behavior not present in 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?

Clearly states the tool performs targeted find-and-replace edits on files, distinguishing it from sibling tools like write_file or delete_file. The verb 'Make' plus 'targeted edits' and resource 'file' are specific.

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?

Provides explicit instruction to ALWAYS read the file first to get exact text, and explains the uniqueness requirement and replace_all behavior. Does not explicitly name alternative tools or exclusions, but the context makes the appropriate use case clear.

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