rtt_read

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

With no annotations, the description carries the full behavioral burden. It usefully discloses experimental status (⚠ 实验性), the firmware prerequisite, and that failures return troubleshooting guidance, but says nothing about blocking behavior, expected duration, or permissions. Adequate but not rich.

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?

Front-loads the purpose and experimental warning, then covers prerequisites, parameters, and failure behavior in a compact block. Each sentence carries information; only minor tightening is possible.

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?

An output schema exists so return-format explanation is unnecessary, and prerequisites/usage are covered. However, for a 3-parameter tool at 0% schema coverage, leaving 'seconds' undocumented means an agent cannot learn the read duration semantics from anywhere.

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 0%, so the description must compensate. It explains cbuffer (control block index, default reads all channels) and probe_serial (specify when multiple debuggers), adding real meaning, but the third parameter 'seconds' is left entirely undocumented in both schema and description.

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+resource ('通过 pyocd 的 RTT 通道读目标板调试日志') and adds differentiating scope: faster than UART and does not occupy the serial peripheral, which distinguishes it from serial_read siblings. An agent can tell what this does and how it differs without opening the schema.

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?

Gives a clear prerequisite (firmware must integrate a SEGGER RTT control block) and a next-step routing hint ('建议先 probe_list 确认调试器'), plus an implicit contrast with UART. It stops short of stating explicit when-not-to-use conditions or naming a specific alternative tool for the fallback case.

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