Write text to a specified path, replacing any existing file and returning bytes written. Use it to save or overwrite notes, logs, or generated content.
Write text to path, replacing any existing file. Returns bytes written.
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | ||
| text | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. It discloses the critical destructive trait ('replacing any existing file') and the return value ('bytes written'), but omits permission requirements, encoding, or error behavior.
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 sentence that front-loads the action and includes only necessary details. Every clause earns its place.
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 an output schema, the description covers the core action and overwrite behavior. However, with zero schema description coverage and no annotations, it leaves parameter semantics and permission/encoding details 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 only restates the parameter names ('text' and 'path') in context, adding little beyond the schema's own 'Path' and 'Text' titles. No format, constraints, or path semantics are provided.
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 and resource: 'Write text to path.' It also clarifies the scope with 'replacing any existing file' and the return value, making it immediately distinguishable from the sibling read/list tools.
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?
Usage is implied by the write action, but the description never states when to use this tool versus alternatives or any prerequisites. For a simple write tool with no competing siblings, the implied usage is adequate but not explicitly guided.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.