session_select

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

With no annotations provided, the description carries the burden of behavioral disclosure. It reveals that the tool selects via value/text/index and that attempting to type into a select has no effect, which is useful behavioral context. However, it does not disclose what happens when no matching option is found, whether the selection triggers change events, or any waiting/error 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?

The description is a single focused sentence that leads with the core action and immediately clarifies the selection methods. The second sentence earns its place by preventing a common misuse. No filler or redundant restatement of the tool name.

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 relatively simple select action, the description covers the action, the element type, and the selection strategies, and it warns against a common mistake. It is missing minor behavioral details like failure handling and does not describe the tabId parameter, but overall an agent has enough information to invoke the tool correctly in most cases.

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 documentation covers 83% of parameters and already defines text, index, value, and selector. The description adds a high-level summary of selection modes but does not materially expand on the schema's parameter descriptions. The uncovered tabId parameter is not explained, so the description does not compensate for the small gap.

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 ('Choose') with a specific resource ('an option in a <select> dropdown') and enumerates the selection modes: by value, visible text, or index. It also distinguishes itself from text filling with the warning that filling a select as a text field does nothing, which separates it from sibling tools like session_fill.

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 clearly indicates when to use the tool: when the target is a <select> dropdown, and how to select the option (by value, text, or index). It implies an exclusion from text-field workflows with 'Filling a select as though it were a text field does nothing,' though it does not explicitly name alternatives like session_fill.

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