get_app_state

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

Annotations already indicate this is a safe, read-only, idempotent operation. The description adds valuable behavioral context: it starts a session if needed, retrieves the key window state, and specifies the output (screenshot and accessibility tree). No contradictions.

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 that cover the essential actions, output, and usage mandate. Every word adds value with no redundancy.

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 simple schema (one well-described parameter) and comprehensive annotations, the description adequately covers what the tool does and when to use it. It mentions the output (screenshot and accessibility tree) but lacks details on error handling or return format. Still sufficient for the complexity.

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?

The input schema has 100% description coverage for the only parameter 'app', which already explains its meaning. The tool description does not add any additional semantic information beyond what is in the schema, resulting in a baseline score of 3.

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 that the tool starts an app use session if needed and retrieves the app's state (screenshot and accessibility tree). It explicitly distinguishes this tool from sibling interaction tools by specifying it must be called before any interaction.

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 a clear usage directive: 'This must be called once per assistant turn before interacting with the app.' This gives strong context for when to use it. However, it does not explicitly discuss alternatives or when not to use it, which would elevate it to a 5.

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