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

Annotations already declare readOnly/idempotent/non-destructive, and the description goes well beyond them: it explains that internal bundles (XPC helpers, view services, SpringBoard) are excluded by default, quantifies the difference (~264 bundles vs ~51 apps on a typical iPad), warns includeInternal produces raw Info.plist dicts and very large output, and notes no automation session is needed. This is exactly the context an agent needs to avoid a bloated or misread call.

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?

Front-loaded with the core action, then the inclusion/exclusion rules, then the optional flag. The bundle-count statistic is somewhat verbose but earns its place by justifying why the default filter exists. Slightly dense but no wasted filler.

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 description compensates by naming the returned fields (bundleId, name, type), fully covering both parameters and their effects, and disclosing the no-session prerequisite. Nothing needed to call this 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 coverage is already 100%, so the baseline is 3, but the description adds real semantic depth for includeInternal — what it turns on (view services, XPC helpers, SpringBoard, raw Info.plist dicts) and that output is very large. udid semantics are left to the schema.

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 ('List the apps installed on an iOS device') and immediately scopes it to user AND system apps, which distinguishes it from generic siblings like device_list_apps or app_list. The agent knows exactly what this returns 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?

Gives clear context: system apps are included by default, internal bundles are hidden unless includeInternal is passed, and notably 'No automation session required' tells the agent it can call this without setup. It does not name the sibling alternatives (device_list_apps, ios_tv_apps) it competes with, so the routing guidance is implied rather than explicit.

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