Start Screen Recording

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

The description discloses the key behavioral trait that the recording runs in the background until explicitly stopped, and that a save path is returned. Annotations already indicate mutability (readOnlyHint=false), and the description adds useful stateful context without contradicting them.

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 three sentences long, front-loads the main action, and every sentence adds necessary information: the action, the background lifecycle, and the return value.

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?

The description, combined with the fully covered schema and annotations, gives the agent everything needed to invoke and manage the recording. It explains how the recording is stopped and what the tool returns, with no missing operational details.

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%, with all three parameters already well documented. The description adds value by stating that the result is a saved path, but it does not need to restate parameter meanings.

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 a specific verb and resource: starting screen recording on a mobile device. It also distinguishes itself from the closely related mobile_stop_screen_recording by explicitly naming that sibling as the stop counterpart.

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 clear operational context: recording runs in the background and is stopped with mobile_stop_screen_recording, which tells the agent how to pair these calls. It does not explicitly discuss alternatives like screenshots, but the lifecycle guidance is sufficient for correct use.

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