write_file

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

Annotations already mark the tool as non-read-only and destructive, so the description goes beyond them by explaining the overwrite guard and optimistic concurrency protection via expected_sha256. It also clarifies the workspace-root confinement, which is useful safety context.

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?

Two concise sentences with no filler. The core purpose is front-loaded, and the overwrite/concurrency caveats follow naturally without 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 plus schema covers the essential behavior: writing a file, workspace-relative path, parent directory requirement, overwrite requirement, and optional SHA check. The absence of an output schema is acceptable for a write operation, and no critical guidance appears missing.

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 75%, and the description compensates for the undocumented overwrite parameter by explaining when it is required. It also adds practical meaning to expected_sha256 by tying it to preventing lost updates.

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 states a specific verb (Write), a specific resource (UTF-8 text file), and a key scope constraint (below the configured workspace root). This clearly differentiates the tool from siblings like read_file, list_directory, and delete_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?

It gives concrete usage conditions: existing files require overwrite=true, and expected_sha256 should be used to prevent lost updates. It does not explicitly name alternatives, but the behavior is specific enough that an agent can decide when to use this tool.

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