computeruse_observe

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

No annotations are provided, so the description carries the full burden. It transparently discloses that the tool captures the screen, optionally extracts UI Automation elements, and returns dimensions, element IDs, and an MCP image. This is sufficient for a read-only observation tool with no hidden mutating behavior.

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?

Two sentences with no wasted words. The action and output are front-loaded, and the usage directive is placed at the end as a natural call to action. Every sentence contributes 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 covers the core action, output shape, and usage context, but there is no output schema and the monitor_index and image_mode behaviors are not explained beyond the input schema. An agent could call the tool with defaults, but would need to inspect the schema for non-default scenarios.

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 only 33%, covering only image_mode. The description partially adds semantics for include_elements via 'optionally visible UI Automation elements', but it never explains image_mode outcomes or monitor_index selection. With low schema coverage, the description needed to compensate more than it does.

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 ('Capture') and names the resource ('current screen', 'visible UI Automation elements'), and explicitly frames the tool as the observation step before click/type decisions. This clearly distinguishes it from siblings like computeruse_execute_step and computeruse_start_session.

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?

'Use this before each click/type decision' is an explicit usage directive that tells the agent when to call the tool. There is no alternative observation sibling, so the lack of a 'when not to use' clause is acceptable.

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