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

Beyond annotations that mark it destructive/open-world, the description discloses sequential execution, stop-on-first-failure behavior controlled by stop_on_error, results indexed by step, screenshot return format differences from browser_screenshot, and the fact that evaluate steps can mutate or delete page state.

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 front-loaded with the core purpose, then gives usage guidance, execution behavior, result behavior, and one important caveat. Every sentence carries useful information for selection or invocation.

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 complex batch tool with no output schema, the description covers the critical return behavior: per-step results are in an indexed results array, failures stop execution unless configured otherwise, and screenshots are base64 strings. Combined with the rich action schema and annotations, this is sufficient for correct invocation.

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 session_id, actions, and stop_on_error. The description still adds useful semantics about stop_on_error behavior and result indexing, though it does not need to re-document the fully enumerated action schema.

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 states a specific verb and resource: execute a sequence of browser actions in a single call against an existing session. It distinguishes itself from the individual browser_* tools by explaining that it reduces round trips and is faster than calling each tool separately.

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?

It gives an explicit usage condition: use this when you already know the full sequence of steps. It also names the alternative strategy, calling each tool individually, and explains why batch is preferable in that situation.

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