Save content to a file, creating it if missing or replacing it if present while automatically creating parent directories.
Write content to a file. Creates the file if it doesn't exist, overwrites if it does. Automatically creates parent directories.
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | Path to the file to write (relative or absolute) | |
| content | Yes | Content to write to the file |
Changes observed during successful MCP inspections.
v0.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full behavioral burden and does well: it discloses that the file is created if missing, overwritten if present, and parent directories are automatically created. The overwrite behavior is important destructive context. It still omits permissions, atomicity, and return behavior, keeping it from a 5.
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 three short sentences, front-loaded with the core action, and every sentence adds useful information. There is no filler or 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?
For a simple two-parameter write tool with no annotations and no output schema, the description covers the key side effects: creation, overwriting, and parent-directory creation. It lacks explicit usage routing against edit, but for the core invocation context it is nearly complete.
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 100%, so both parameters are already documented in the input schema. The description adds no additional parameter meaning, formatting, path constraints, or encoding details. The baseline of 3 is appropriate when the schema does the heavy lifting.
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 gives a specific verb and resource: 'Write content to a file.' It also clarifies create/overwrite behavior, which helps distinguish it from a pure edit tool. However, it does not explicitly name the sibling tool edit or contrast the two, so it stops short of full sibling differentiation.
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 states what the tool does behaviorally but gives no explicit when-to-use guidance or alternatives. It does not say to use this for full-file writes and edit for partial modifications, nor does it mention prerequisites or exclusions. An agent must infer the appropriate usage context.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.