preprocess

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description usefully explains the output content (preprocessed source) rather than just repeating that it's a read, but says nothing about permissions or how this relates to the compile pipeline beyond 'instead of compiling.'

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?

Two tight sentences: the first front-loads what the tool does, the second gives the use case. 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?

For a simple read-only operation, the description covers purpose, output, and use case, and annotations carry the safety profile. The lack of an output schema is mitigated by the description stating that the preprocessed source is printed, though it could note whether output is streamed or returned.

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 100%, so all four parameters are already documented in the schema. The description adds no parameter-level meaning (e.g., how fqbn or buildProperties affect preprocessing), so the baseline 3 is appropriate.

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 ('Print') and resource ('the preprocessed sketch source') and clarifies the transformation (macros expanded, headers resolved). It implicitly contrasts with 'compile' via 'instead of compiling,' though it doesn't name the sibling tool directly.

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 use case: 'debugging #define / conditional-compile issues.' This tells the agent when the tool is valuable, but offers no explicit exclusions or named alternatives for other debugging scenarios.

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