MCP J-Link Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. While it indicates this is a read operation, it doesn't disclose important behavioral aspects: whether this requires the target to be halted, what happens if the register is invalid, whether there are permission requirements, or what the typical response format looks like. For a hardware debugging tool with zero annotation coverage, this leaves significant gaps.

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 appropriately concise with two sentences that both earn their place. The first states the core purpose, and the second provides crucial parameter semantics. The structure is front-loaded with the main purpose first. It could be slightly improved by integrating the parameter documentation more seamlessly rather than as a separate 'Args:' section.

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 that there's an output schema (which handles return value documentation), the description's main job is to explain purpose and parameters. It does this adequately for the single parameter. However, for a hardware debugging tool with no annotations, it should ideally mention behavioral constraints like requiring the target to be halted or connected. The presence of an output schema raises the baseline, but there are still contextual gaps.

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?

With 0% schema description coverage (the schema only shows 'register' is an integer), the description provides essential semantic information that compensates fully. It explains that the integer parameter represents register indices with specific mappings (0=R0, 1=R1, ..., 13=SP, 14=LR, 15=PC, 16=xPSR). This transforms an abstract integer parameter into meaningful register identifiers that the agent needs to use the tool correctly.

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's purpose as '讀取指定的 CPU 暫存器值' (read specified CPU register value), which is a specific verb+resource combination. It distinguishes itself from siblings like jlink_register_read_all (which reads all registers) and jlink_register_write (which writes to registers). However, it doesn't explicitly mention the J-Link debugger context that's implied by the tool name prefix.

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 no guidance on when to use this tool versus alternatives. It doesn't mention when to use jlink_register_read versus jlink_register_read_all, nor does it specify prerequisites like requiring an active J-Link connection. The only implicit guidance comes from the parameter documentation showing register mappings.

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