Fulcra MCP Server

Start File Upload

start_file_upload

Initiate a file upload from the file manager panel by specifying the destination path and file size; optional MIME type is inferred when omitted.

Instructions

Starts an upload from the file manager panel.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "path": "<path>",
      "size": "<size>"
    },
    "name": "start_file_upload"
  }
}

Input Schema

Name	Required	Description
`path`	Yes	Full path to write to.
`size`	Yes	File size in bytes.
`content_type`	No	MIME type; guessed if omitted.

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

Changed6 schema fields changedv1.18.7Oct 23, 2026

removedInput schema / properties / content_type / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

removedInput schema / properties / content_type / default
```
Removed value: -null
```

changedInput schema / properties / content_type / description

Previous value: -"Its MIME type; guessed from the name when left out."New value: +"MIME type; guessed if omitted."

addedInput schema / properties / content_type / type
```
Added value: +"string"
```

changedInput schema / properties / path / description

Previous value: -"The full path to write to, e.g. \"/reports/q3.xlsx\". An existing\nfile at that path gets a new version."New value: +"Full path to write to."

changedInput schema / properties / size / description

Previous value: -"The file's size in bytes."New value: +"File size in bytes."

Addedv1.2.4Oct 14, 2026

TDQS

C2.9/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The annotations already state that this is not read-only, not destructive, and closed-world. The description adds little beyond that: it does not explain that this likely initiates an upload session, whether follow-up chunk calls are required, or what the caller should do next.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single front-loaded sentence with little waste. However, the trailing "from the file manager panel" is vague and does not meaningfully improve the definition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Although an output schema exists and annotations cover safety, the description omits the upload workflow relationship with upload_file_chunk. For an initiation tool in a file upload family, that context is important for correct invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so path, size, and content_type are already documented sufficiently in the schema. The description adds no additional parameter meaning, which is acceptable given full schema coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description gives a specific verb and resource: it starts an upload. It does not distinguish this tool from the closely related upload_file_chunk sibling, and the phrase "from the file manager panel" adds UI context rather than clarifying the tool's role.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no guidance on when to use this tool versus upload_file_chunk, write_file, or other file-related siblings. It also does not mention prerequisites or the upload workflow.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server