native_build

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

Annotations (openWorldHint=true, idempotentHint=false) convey non-idempotent, external effects. The description adds that output streams to timeline and notes the necessary native toolchain, providing useful behavioral context beyond annotations.

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 extremely concise: two sentences cover action, method, prerequisites, and post-condition. No fluff, front-loaded with the main purpose.

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 the complexity of native builds, the description covers prerequisites (native toolchain), output destination (timeline), and follow-up tool. No output schema exists, but the description implies streaming output, which is sufficient.

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 coverage is 100% with descriptions for both parameters (cwd and platform). The description mentions 'active pane' which aligns with schema's default for cwd, but adds no extra semantics beyond what the schema already provides.

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 builds and launches a native dev build for the active pane, using specific commands (expo run:ios/android). It distinguishes itself from browser and other dev tools by specifying 'native build' and 'Cockpit-only'.

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 usage context: 'Cockpit-only (needs the native toolchain)' and advises follow-up with native_open after boot. It does not explicitly state when not to use, but the prerequisites imply exclusion.

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