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

With no annotations, the description carries the full burden, and it does disclose the cost ('Costs 1 mcp_call'), which is genuinely useful behavioral context. However it says nothing about what happens on multiple matches, element-not-found, or whether the click awaits navigation, so the disclosure is partial.

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?

Two short sentences, zero waste, with the primary action front-loaded ahead of the cost note. Nothing could be cut without losing information.

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 an interaction tool with no annotations, no output schema, and fully undocumented parameters, the description is too thin. An agent lacks guidance on session lifecycle, match ambiguity, and failure behavior before committing a paid call.

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 0% across two parameters, so the description must compensate. It implies the 'description' param accepts text/label/CSS-selector strings, which helps, but the 'session' parameter (default 'default') is never explained and no format examples are given for the selector syntax.

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?

Clear verb+resource: 'Click an element' with three accepted targeting modes (visible text, label, CSS selector). It doesn't distinguish itself from the sibling browser_click_at, which an agent would need to choose between, but the core action is unambiguous.

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?

No statement of when to use this versus browser_click_at, browser_fill, or other browser siblings, and no prerequisites such as an existing session. The agent must infer usage entirely from the tool name.

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