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

Annotations only provide a title, no readOnly/destructive hints. The description implies a mutating action (click) but doesn't disclose side effects like navigation, form submission, or whether it requires a session. It doesn't contradict annotations, but adds minimal behavioral context beyond the schema.

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, concise sentence that directly states the tool's purpose. No wasted words.

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?

Given the tool's simplicity and full schema coverage, the description is adequate but lacks context about when to use it vs session_click, and doesn't mention potential side effects or return behavior. For a tool with no output schema and minimal annotations, it could provide more guidance.

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 all three parameters. The description adds no additional meaning beyond what the schema provides, so 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 clearly states the action ('Click an element on a webpage') and the method ('using CSS selector'). It distinguishes from siblings like session_click by implying a one-off action without session management, though it doesn't explicitly contrast with session_click.

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 implies usage for clicking elements on a webpage, but provides no explicit guidance on when to use this tool versus session_click or other session-based tools. It doesn't mention prerequisites like page load or session creation.

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