send_keys

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

With no annotations, the description carries the full burden of explaining behavior. It does disclose that keys go to the focused element unless a selector is provided, which is useful. However, it does not mention what happens when no element is focused, whether the selector is awaited or scoped by the 'by' parameter, or any error/side-effect 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 compact and front-loaded: it states the action and target in the first sentence, then provides concrete key-name examples in the second. Every word earns its place with no fluff or repetition.

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 simple keyboard-action tool, the core call pattern is adequately conveyed. However, given no output schema and no annotations, the description omits useful context about timeout behavior, selector strategy ('by'), and how this tool differs from 'type_text'. It is sufficient for basic use but not fully complete.

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 only 50%: 'key' and 'selector' have descriptions, while 'by' and 'timeout' do not. The description adds useful examples for the 'key' parameter and clarifies that 'selector' focuses an element first, but it does not explain the meaning of 'by' or 'timeout', so it only partially compensates for the schema gaps.

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 clearly states the action: 'Send a key or key combination' to either the focused element or a selector-targeted element. It distinguishes itself from typical text-entry behavior by focusing on special keys and combos, though it does not explicitly differentiate from the sibling 'type_text' tool.

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 examples ('tab', 'enter', 'ctrl+a') imply that this is for keyboard-level input rather than free text, and it mentions the optional selector for targeting a specific element. However, it provides no explicit guidance on when to use this versus 'type_text' or other input-related siblings, nor any exclusions or preconditions.

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