upload

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

Annotations declare readOnlyHint=false, destructiveHint=true, idempotentHint=true, so the safety profile is already covered. The description adds real value beyond that: it discloses the implicit compile step, the board-attach dependency for omitted params, and the port-contention failure mode with Serial Monitor. It doesn't describe post-flash board reset behavior or return output, but that's a minor gap against the annotation coverage.

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, each earning its place: the core action, the parameter-omission rule, and the critical precondition. Front-loaded with the primary action and 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 7-parameter mutation tool with no output schema, the description covers the main preconditions, the implicit compile behavior, and parameter defaults. Residual gaps are small: no explicit statement about board reset after flash or the relationship to 'upload-and-monitor', but annotations carry the safety profile.

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 the schema already documents all seven parameters, including the note that fqbn/port can be omitted if set via board-attach. The description's mention of that same omission rule adds an explanation of why (saved via board-attach), but no syntax or format detail beyond the schema. Baseline 3 applies.

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 specific verbs and resources: compile-if-needed and flash a sketch to a connected board. This is clearly distinguishable from the sibling 'compile' (compile only) and implies a superset operation. It doesn't explicitly name 'upload-and-monitor' as the alternative, so sibling routing is only partially spelled out.

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 concrete usage context: fqbn/port may be omitted when previously set via board-attach, and a hard precondition that Serial Monitor must be closed because it holds the port lock. It stops short of an explicit when-to-use-this-vs-'upload-and-monitor' comparison, which is the nearest ambiguous alternative.

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