file_write

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

With no annotations, the description carries the full burden. It does disclose a useful side effect (creating parent directories) and an auth requirement (file.write permission), but it omits critical behavior such as whether existing file content is overwritten or if the operation is atomic. This is a significant gap for a write 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 two succinct sentences, front-loaded with the primary action and followed by two essential behavioral details. There is no redundant or filler content, making it highly efficient for an agent to parse.

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?

For a simple two-parameter write tool with no output schema, the description covers the core purpose, prerequisite, and directory creation. However, it misses overwrite semantics and return behavior, which are relevant for a mutation tool. It is adequate but has clear gaps that could lead to incorrect assumptions.

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 coverage is 100% and the description does not add any meaning beyond the schema; the schema already describes path and content clearly. The baseline of 3 applies because parameters are fully documented in the schema, and the description does not need to compensate.

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 begins with 'Write content to a file', a specific verb and resource that clearly distinguishes this tool from siblings like file_read and file_delete. It also adds helpful detail about creating parent directories, which further clarifies the tool's scope.

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 the tool (when you need to write content to a file) and mentions a permission prerequisite, but it does not explicitly compare with alternatives or state when not to use it. The purpose is clear enough to infer usage, but no direct guidance is given.

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