Click an element

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

readOnlyHint=false already marks this as a write-ish interaction, and the description adds genuine behavioral context the annotations do not: it dispatches a real trusted pointer sequence (move, down, up) at the element's centre, which matters for pages that distinguish trusted events. It omits failure behavior (no match, hidden element), auto-scroll, and waiting, keeping it out of 5 territory.

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?

One sentence, front-loaded with the action and resource, with the mechanism qualifier immediately after. Nothing is padded and nothing is buried.

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 two-parameter interaction tool with an annotation and full schema coverage, the definition covers what the tool does and how it acts on the page. It does not cover what happens when the selector matches nothing or the element is obscured, which is the main remaining gap.

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 both parameters are already documented in the schema. The description reinforces that the selector resolves to the first match only, but says nothing about the `context` tab-id parameter or selector syntax; 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?

States a specific verb and resource ("Click the first element matching a CSS selector") plus the mechanism ("real mouse action... at its centre"), which separates it from coordinate-based browser_mouse_action and synthetic clicks via browser_evaluate. It never names a sibling or says what it does not do (e.g. no hovering, no typing), so it falls short of a 5.

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 is only implied by the tool's obvious semantics; the description gives no when-to-use/when-not, no mention of alternatives such as browser_mouse_action for coordinate clicks or browser_hover for non-clicking pointer moves, and no prerequisites such as the element needing to be visible.

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