CNCjs MCP Server

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

With no annotations provided, the description carries full burden and effectively discloses key behavioral traits: it's a destructive action ('immediately halts all motion'), uses a specific protocol ('GRBL soft reset'), and implies urgency. However, it doesn't detail side effects like resetting machine state or requiring reconnection.

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?

Extremely concise and front-loaded: the first phrase states the core action, followed by technical details and usage context in just two sentences, with zero 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?

For a zero-parameter, no-annotation tool with no output schema, the description is nearly complete: it explains purpose, usage, and mechanism. However, it lacks details on post-execution state (e.g., machine reset effects) or error handling, leaving minor 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?

The tool has 0 parameters with 100% schema coverage, so the baseline is 4. The description adds no parameter information, which is appropriate given no parameters exist, maintaining the baseline score.

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 specific action ('immediately halts all motion') and mechanism ('via GRBL soft reset (0x18)'), distinguishing it from sibling tools like 'stop_job' or 'feed_hold' by emphasizing its emergency nature and immediate effect.

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?

Explicitly states when to use ('Use in any dangerous situation'), providing clear context for its application versus alternatives like 'stop_job' (normal stopping) or 'feed_hold' (temporary pause), with no misleading exclusions.

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