bot_download_fileDownload a file received by a Bale bot (up to 20 MB), save it locally without overwriting, and return the saved file path.
Download a file someone sent the bot (max 20 MB) and return its local path. Never overwrites (-1, -2, ... suffix).
| Name | Required | Description | Default |
|---|---|---|---|
| folder | No | Folder to save into. Default ~/.bale-mcp/files. | |
| file_id | Yes | file_id from a received message. |
Changes observed during successful MCP inspections.
v0.2.0Input schema / properties / file_id / descriptionPrevious value: -"file_id of a photo, document, voice, video or audio message."New value: +"file_id from a received message."Input schema / properties / file_id / titleRemoved value: -"File Id"Input schema / properties / folder / titleRemoved value: -"Folder"Input schema / titleRemoved value: -"bot_download_fileArguments"Output schema / (root)Previous value: -{
- "additionalProperties": true,
- "title": "bot_download_fileDictOutput",
- "type": "object"
-}New value: +nullv0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the write-but-non-destructive, non-idempotent, open-world profile, and the description adds genuinely new context: a 20 MB size ceiling and the never-overwrite (-1, -2, ...) naming rule, which explains why idempotentHint is false. It does not mention failure behavior or whether the target folder is auto-created, so it falls short of a 5.
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?
Two tight sentences with zero filler; the core action and size limit lead, with the overwrite rule as a useful secondary detail.
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 two-parameter tool with no output schema, the description covers the action, the size limit, the return value (local path), and overwrite behavior. It omits error/failure handling and folder-creation semantics, which keeps it just short of complete.
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 file_id and folder (with its default) are documented in the schema. The description adds no syntax, format, or constraints for either parameter, so the baseline 3 applies.
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 (download), resource (a file someone sent the bot), scope constraint (max 20 MB), and the return value (its local path). This cleanly separates it from bot_send_file and the other bot_* siblings without ambiguity.
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 phrase 'a file someone sent the bot' implies the precondition that file_id must come from a received message, and the schema reinforces this. However, no alternative tool is named and there is no when-not guidance (e.g., how to obtain the file_id, what to do for files the bot sends).
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.