Perform one observed MAX+plus II action

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

Annotations already declare destructive=true, idempotent=false, openWorld=true, so the safety profile is covered. The description adds real context beyond that: it executes exactly one input, uses MCP-owned Win32/UIA rather than host-specific calls, and always returns a fresh screenshot/tree, telling the agent state must be re-inspected after each action.

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?

Three sentences, front-loaded with the action scope, followed by implementation note, preconditions and the inspect loop. Dense but mostly economical; 'no host-specific calls' is a slightly opaque phrase that does not fully earn its place.

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?

For a 6-parameter, nested-object mutation tool with no output schema, the description covers the essential call contract: prerequisites, one-action scope, and the fresh screenshot/tree return value. It leaves operationId retry/caching semantics entirely to the schema, but those are documented there.

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 the nested 'parameters' property documents each action's arguments in detail. The description only restates the observationId/windowId freshness requirement, adding little syntax or format meaning beyond the schema, so the baseline 3 applies.

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?

Specific verb ('Directly execute') plus a precise resource and scope ('ONE click, hover, key chord, Unicode text entry, value change, drag, scroll, secondary UI action or activation'). The single-action framing plus 'return a fresh screenshot/tree' cleanly separates it from the observation-oriented siblings like desktop_observe.

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?

States the precondition ('Requires latest observationId/windowId') and the workflow expectation ('Inspect after every input'), which tells the agent to re-observe between actions. It does not explicitly name desktop_observe as the alternative, so the routing is implied rather than spelled out.

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