Verify a file's UTF-8 encoding and optionally repair UTF-16 corruption by re-saving as UTF-8.
Check whether a file is valid UTF-8 and optionally fix UTF-16 corruption.
| Name | Required | Description | Default |
|---|---|---|---|
| fix | No | Re-save as UTF-8 if corrupted (default: false) | |
| path | Yes | Absolute path to the file |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden of behavioral disclosure. It mentions optional fixing of UTF-16 corruption, implying a file modification, but does not explicitly state that the file will be overwritten or that the operation is destructive. It also fails to disclose the return value or error behavior, leaving the agent uncertain about side effects.
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 sentence with no filler. Every word contributes to stating the core action and the optional fix. It is highly concise and front-loaded, though it may be too sparse for full completeness.
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 tool that both checks and can modify files, the description is incomplete. It does not state what the tool returns (e.g., boolean, report), whether it requires write permissions when fix=true, or how it handles invalid UTF-8. With no output schema and no annotations, these gaps leave the agent uncertain about invocation and handling results.
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% – both 'path' and 'fix' have descriptive properties. The description adds no additional meaning beyond the schema, such as path format expectations or the exact effect of 'fix'. Baseline of 3 applies because the schema already documents the parameters adequately.
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 ('check') and resource ('file is valid UTF-8'), and also mentions an optional fix action. It clearly distinguishes from siblings utf8_write and utf8_replace, which focus on writing/replacing content, while this tool verifies validity.
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 provides no guidance on when to use this tool versus its siblings. It does not mention scenarios like pre-write validation or troubleshooting, nor does it say when not to use it. The agent is left to infer usage context from the name and siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.