replace_in_file

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

Annotations already indicate destructive and non-read-only behavior. The description adds meaningful context about optimistic concurrency and server-side execution, which clarifies the tool's operational model beyond the annotations.

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?

A single, well-structured sentence that front-loads the action and distinguishing feature. Every word adds value with no redundancy.

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 is adequate for a simple replacement tool, but gaps remain: expected_count semantics, server_id usage, and failure behavior when the old snippet is not found or expected_sha256 mismatches. The output schema may cover return values, but parameter semantics are partly unaddressed.

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 description coverage is 0%, so the description must compensate. It explains the core concept of exact snippet matching (old/new) and concurrency (expected_sha256), but leaves expected_count and server_id unexplained, forcing inference from names.

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 replaces an exact snippet server-side with optimistic concurrency, which is a specific verb + resource. It also distinguishes from whole-file writes found in sibling tools like write_file and safe_write_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 implies when to use this tool: when you need a targeted snippet replacement without rewriting the entire file. It does not explicitly name alternatives or exclusions, but the 'avoiding whole-file model output' phrase gives clear context.

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