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

With no annotations provided, the description carries the full burden of behavioral disclosure and does so thoroughly. It discloses the per-launch override, the fallback between RDSRunner and pymobiledevice3 DVT launch, that it reports which mechanism was used, and the legacy-app locale caching caveat with a concrete remediation (kill and re-call). This is exemplary transparency.

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 dense but every sentence earns its place: purpose, use case, override scope, session fallback mechanism, and a legacy caveat with a fix. The main idea is front-loaded, and no sentence is filler or redundant with the schema.

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 4-parameter launch tool with no annotations and no output schema, the description is remarkably complete. It covers purpose, when to use it, behavioral edge cases, session handling, and the legacy-cache workaround. Nothing critical for an agent 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?

Schema description coverage is 100%, so the baseline is 3. The description adds a Spanish example and explains why the language override matters, but it does not add substantial parameter-level semantics beyond what the input schema already documents. It is neither deficient nor additive enough to exceed baseline.

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 uses a specific verb and resource: 'Launch an iOS app forced into a specific language / locale.' It clearly distinguishes itself from language-setting tools ('without changing the device's system settings') and from plain launch tools, so an agent can tell it apart from ios_launch_app and ios_set_device_language immediately.

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?

It explicitly identifies the primary use case: 'Useful for QA testing app localization.' It also clarifies the per-launch override semantics and the reversion to system language. However, it stops short of explicitly naming sibling alternatives and stating when not to use them, so the when-not guidance is implied rather than stated.

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