is_multi_select

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

Annotations already provide readOnlyHint=true, so the safe read nature is covered. The description adds value by revealing that the check relies on the 'UIA Selection pattern', giving the agent insight into the underlying mechanism. It does not contradict annotations. No mention of error cases or prerequisites, but for a simple query that's acceptable.

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?

A single, front-loaded sentence of 20 words. Every word serves a purpose: verb, subject, condition, and even the underlying technology ('UIA Selection pattern'). No redundancy or filler.

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 tool's simplicity (one parameter, no output schema, readOnly annotations), the description adequately explains the tool's purpose. However, it could improve by explicitly stating the return type (boolean) since no output schema is present. The current description implies a yes/no answer but doesn't guarantee it.

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% with one required parameter (elementId) that is well-described as 'Element ID returned by find_element'. The tool description adds no additional parameter context beyond what the schema already provides. Baseline 3 is appropriate since the schema does the heavy lifting.

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 'Check whether' and clearly identifies the resource: 'a container (e.g. ListBox) allows multiple items to be selected via the UIA Selection pattern'. This directly distinguishes it from sibling tools like is_element_selected (which checks a single element's selection state) and is_element_enabled (checks enabled state).

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 implies the tool should be used when you need to determine multi-select capability of a container, but it gives no explicit context about when NOT to use it or alternatives. For example, it doesn't mention that is_element_selected or get_selected_items might be more appropriate for checking actual selection state. Usage guidance is only implied, not explicit.

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