compile

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 adds that it returns memory usage and errors, but says nothing about build failures timing, dependency/board-attach requirements, or rate/latency behavior.

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?

Three short sentences, front-loaded with the core action, then the hardware-free benefit, then the return contents. 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?

With no output schema, the brief mention of memory usage and errors covers the return shape adequately, and 100% schema coverage handles parameters. The main remaining gap is routing guidance relative to sketch-validate and preprocess.

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 seven parameters (fqbn, verbose, libraries, sketchPath, boardOptions, additionalUrls, buildProperties) are already documented with examples in the schema. The description adds no parameter meaning beyond that.

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?

Specific verb+resource ('Compile an Arduino sketch for a board') that clearly conveys the action. However, it does not distinguish itself from the sibling sketch-validate, which an agent may confuse with a hardware-free code check.

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 phrase 'Verifies code without needing hardware' implies the build-without-upload scenario, but no explicit when-to-use or when-not-to-use guidance is given, and no alternative (e.g. sketch-validate, upload, preprocess) is named or contrasted.

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