Check if a file or directory path exists and get its type, size, and last modified time before reading or editing it.
Check whether a path exists and get its type, size and modification time.
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | Path |
Changes observed during successful MCP inspections.
v1.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is fully covered by structured data. The description usefully discloses the concrete return fields (type, size, modification time), which is the main value it adds and which matters since there is no output schema. It does not state behavior on missing paths (error vs. false) or permission requirements.
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 front-loaded sentence that conveys purpose and return values with zero waste. Size is well matched to a simple one-parameter tool.
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 read-only probe with full annotation coverage and no output schema, the description adequately conveys both the operation and the returned fields. It only falls short on edge-case behavior for non-existent paths and routing away from check_files.
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?
Single parameter with 100% schema coverage, so the schema already documents 'path' (albeit minimally as 'Path'). The description adds no format or meaning beyond what the schema provides, making baseline 3 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?
States a specific verb and resource (check path existence) plus the returned attributes (type, size, mtime), so the purpose is unambiguous. It does not distinguish itself from the overlapping sibling check_files, leaving some ambiguity about which to pick.
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?
There is no when-to-use or when-not-to-use guidance, and no mention of the natural alternative check_files or the broader list_directory. The agent must infer usage context on its own.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.