Build Xcode Version

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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false), so the bar is lower. The description adds value by disclosing the return envelope {ok, exit_code, stdout, stderr} and noting that stdout carries the version lines, which annotations cannot express.

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, front-loaded lines: purpose, when, returns. No sentence is filler and the most decision-relevant information (what it does, when to call it) comes first.

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 no-argument read-only probe, the description covers purpose, trigger condition, and the shape of the result. An output schema exists, but the extra note about stdout holding the version lines is a useful pointer, and nothing needed to call it correctly is missing.

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?

Zero parameters, so there is nothing to document and the baseline is 4. The description correctly spends no words on argument semantics.

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 and resource ('Return the installed Xcode version') with no ambiguity, and the context of use ('before build_* tools') cleanly separates it from the build_* siblings. An agent can pick this out without opening the schema.

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 names the when ('a quick check that xcodebuild works before build_* tools'), which is genuinely actionable routing guidance. It does not name a when-not or an alternative diagnostic tool (e.g., env_doctor, config_doctor) that an agent might otherwise consider.

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