Write content to a file with options to overwrite or append, and select encoding (UTF-8, ASCII, binary, base64) for precise file management.
Write content to a file with optional append mode
| Name | Required | Description | Default |
|---|---|---|---|
| mode | No | Write mode: append to existing file or overwrite | overwrite |
| content | Yes | Content to write to the file | |
| encoding | No | File encoding | utf8 |
| file_path | Yes | Path to the file to write to |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It only mentions append vs. overwrite mode, but does not disclose whether the tool creates missing files, how it handles existing files, error behavior, or what the return value indicates. For a mutating filesystem operation, this is a significant gap.
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 a single, front-loaded sentence with no filler. Every word contributes to the core purpose, and the append mode detail is placed prominently. This is an exemplar of concise specification.
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?
Given there is no output schema and no annotations, the description should explain behavior such as whether the file is created if absent, whether overwrite is the default, and what the tool returns on success or failure. None of this is present, leaving an agent with critical missing context for a file-mutation operation.
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 the schema already documents all parameters, including mode and encoding enums with defaults. The description only reinforces the mode parameter by mentioning append mode, adding no new meaning beyond the schema. Baseline 3 is appropriate.
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 action (write) and resource (file), and mentions the optional append mode, which conveys that the default is overwrite. It is specific enough to distinguish from read/analysis siblings, though it does not explicitly name an alternative write tool (there is none in the sibling list).
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 usage for writing to files but provides no explicit guidance on when to use this tool versus alternatives, nor any exclusions. Since all siblings are read/analysis tools, the use case is obvious, but the description leaves that inference entirely to the agent without stating it.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.