browser_set_combobox

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

With no annotations, the description carries the full transparency burden. It clearly discloses the internal interaction sequence: click, type query, wait for listbox, click option. It also notes configurable waiting behavior and multi-select. Minor omissions like whether existing selections are cleared before setting values keep it from a 5.

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 tightly worded sentences front-load the core action, then explain the internal flow, multi-select support, and when to use the tool. There is 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?

The description covers the operation's workflow, multi-select behavior, and the key alternative comparison. All six parameters are fully documented in the schema. The main gap is the absence of return-value or post-condition information, but that is minor for a UI interaction tool with no output schema.

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%, so the schema already documents every parameter fully. The description adds context about multi-select and the lazy-rendering use case, but does not add meaningful parameter semantics beyond what the structured schema provides. Baseline 3 is appropriate.

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 names a specific verb+resource ('Set value(s) on an autocomplete/combobox input') and explains the exact multi-step flow it automates. It explicitly distinguishes this from browser_select_option, making its purpose and scope immediately clear.

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?

Usage guidance is explicit: 'Use when browser_select_option fails because options render lazily after typing.' This tells the agent exactly when to choose this tool over the closest sibling, and the multi-select example adds real context.

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