Android app Info

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

Annotations already cover read-only, idempotent, open-world, and non-destructive hints. The description adds valuable behavioral detail: that a not-installed package is a normal answer (installed:false with a note) rather than an error, which prevents the agent from misinterpreting a common outcome. It also mentions the underlying command (dumpsys package) and the cheapness, providing 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 a single paragraph, front-loaded with the main purpose and then details. It is informative without being verbose; each sentence contributes (purpose, fields, non-error behavior, cheapness). While not bulleted, it is well-structured and skimmable. Slight length keeps it from 5.

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 fully specifies the return values (version, SDK, paths, times, installer, system status, running state) and explicitly handles the not-installed case. It also provides usage context (cheap check). For a read-only inspection tool, nothing essential 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%, and both parameters have descriptive text (device serial context, package name pattern/example). The description adds minimal extra parameter meaning—only implying that package_name refers to an installed package, which is already in the schema. Baseline 3 is appropriate.

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 names a specific verb ('Read') and resource (facts about an installed package via dumpsys package), then enumerates exact fields (version, SDK, paths, times, installer, system status, running state). It clearly distinguishes from siblings like android_list_apps (list) and android_processes (processes) by specifying what it returns.

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 states a clear context: 'this is the cheap way to check a package name before acting on it,' guiding agents on when to use it. It does not explicitly name alternatives or exclusions, but the context is sufficient for selection among siblings.

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