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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, so the mutation profile is known. The description adds that move+resize are applied atomically in one call and that identity/bounds should be checked first; it does not say what happens on invalid coordinates, out-of-bounds values, or a missing window.

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 tight sentences, with purpose front-loaded and the precondition second. No filler, though the second sentence is advisory and slightly under-specified ('monitor bounds' assumes the agent knows how).

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?

An output schema and full schema descriptions carry most of the load, so the description needn't explain returns. However, for a 10-parameter mutation tool it says nothing about window-selector precedence (id vs app vs pid vs title) or failure behavior, leaving gaps the structured fields don't fill.

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 coverage is 100%, so the schema already documents all 10 parameters including the backend enum and the id/app/pid/title selectors. The description only echoes 'explicit coordinates and dimensions' without adding format or unit detail beyond what the schema supplies.

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?

States a specific verb pair and resource: 'reposition and resize a specific desktop window.' The phrase 'in one action' distinguishes it from the separate window_move and window_resize siblings, though it never names them explicitly.

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 to...' plus 'verify its identity and monitor bounds beforehand' gives an implied precondition, but it never says when to prefer this over window_move / window_resize or what to do if the target is ambiguous. Usage is implied rather than routed.

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