serial_upload

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

With no annotations, the description carries the full behavioral disclosure burden. It clearly states that the operation blocks, logs progress to stderr, and explains the two timeouts and their distinct behaviors (idle_timeout for real failure, timeout as a safety cap with a suggested value). This is substantial and goes beyond simple 'uploads a file.'

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 two sentences, front-loaded with the purpose, and every sentence conveys essential information: the upload mechanism, blocking behavior, stderr logging, and timeout semantics. No wasted words.

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?

Given 7 parameters, no output schema, and no annotations, the description is fairly complete. It covers prerequisites, blocking behavior, progress logging, and both timeouts. It does not detail the return value, but the overall workflow is well explained for a tool of this complexity.

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?

The schema description coverage is 100% and every parameter already has a detailed description. The tool description adds some context about the timeouts but mostly summarizes what the schema already states. Baseline 3 is appropriate since the schema does the heavy lifting.

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 action ('Upload a binary file'), the method ('over ZMODEM via an existing serial session'), and the resource. It implicitly distinguishes itself from siblings like ssh_sftp_upload and serial_download by specifying ZMODEM and serial session, and mentions the required rz command.

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 clear context for when to use the tool: with an existing serial session and a device having lrzsz installed. It does not explicitly mention when not to use it or alternatives, but the prerequisites and method are clearly specified, making the context strong enough.

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