Send a file to a chat as the authenticated user. Requires a file key obtained from a prior upload.
[User Identity] Send a file as the logged-in user. Requires file_key (upload via Official API first).
| Name | Required | Description | Default |
|---|---|---|---|
| chat_id | Yes | Target chat ID. Numeric preferred; oc_xxx is auto-resolved (v1.3.7 C1.4). | |
| file_key | Yes | File key from upload | |
| file_name | Yes | Display file name | |
| root_id | No | Thread root message ID (optional) |
Changes observed during successful MCP inspections.
v1.3.10Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must disclose behavioral traits. It reveals that the file is sent as the user and requires a pre-uploaded file_key, but it does not discuss potential side effects, permissions, rate limits, or the return value. The prerequisite is useful but the description is otherwise minimal.
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 that immediately states the purpose and key requirement. Every word earns its place with no redundancy or filler.
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?
The schema fully explains all parameters, and the description provides the critical prerequisite of uploading the file first. The tool is straightforward, and the information is sufficient for correct invocation, though the lack of output schema means return values are not described.
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 parameters are fully documented in the schema. The description adds a small extra context about file_key needing to come from the Official API, but overall it does not significantly enhance parameter understanding beyond the schema.
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 'Send a file as the logged-in user' uses a specific verb and resource, clearly indicating the action and recipient identity. It distinguishes this tool from siblings like send_image_as_user, send_post_as_user, and send_message_as_bot by emphasizing 'file' and 'logged-in user'.
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 a clear prerequisite: file_key must be obtained via the Official API first. It also clarifies that the action is performed as the logged-in user, which differentiates it from bot-send tools. However, it does not explicitly name alternative tools or exclusion criteria.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.