serial_read

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

With no annotations, the description carries the full burden for behavioral disclosure. It reveals a critical trait: concurrent access with serial_exec/serial_write corrupts the output buffer. However, it does not mention return format or whether it blocks, but the concurrency warning is a major safety disclosure.

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 only two sentences: first gives the purpose, second is a critical warning. No fluff, perfectly front-loaded, and every sentence earns its place.

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 read tool with well-documented parameters and no output schema, the description covers the essential context. The concurrency warning addresses the main risk, and the purposes is clear. It could mention buffering behavior briefly, but the clear parameter in schema partially covers that.

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 input schema covers both parameters (session_id and clear) with 100% coverage, so the description adds no extra parameter meaning. Baseline of 3 is appropriate because the schema already 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 'Read output from a serial shell session' with a specific verb and resource. It distinguishes itself from siblings by explicitly warning about concurrency with serial_exec/serial_write, making its role clear.

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 gives an explicit when-not-to-use guideline: 'Do NOT call this concurrently with serial_exec/serial_write on the same session_id.' This is a strong usage exclusion that helps the agent avoid a critical error, and it implies the tool's primary purpose is to read serial output.

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