upload_file

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

Annotations only include destructiveHint: false, indicating no destructive behavior. The description adds context about the file being attached to messages and returning a file ID for later use. It does not contradict annotations and provides meaningful behavioral insight beyond the annotation.

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 concise with two sentences, front-loading the action 'Upload a file to a channel'. Every sentence provides essential information without redundancy.

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 description covers the main action, return value, and relationship to messages. Given the simple nature of the tool and that an output schema exists, it is fairly complete. Minor omissions like file size limits or accepted types are not critical for basic usage.

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 schema already documents each parameter. The description does not add additional meaning beyond stating the file will be attached to messages, which is implicit from the tool's purpose. Thus, the description adds marginal value over 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 clearly states the tool uploads a file to a channel and attaches it to messages. It distinguishes from sibling tools like get_file_info which only retrieve file details, and no other upload tool exists, making the purpose unambiguous.

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 explains that the file will be attached to messages in the specified channel, giving clear context for when to use this tool. However, it does not explicitly mention when not to use it or provide alternatives, such as using existing file IDs from other tools.

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