browser_act

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

Beyond the sparse annotations, the description discloses that calls return a delta observation, that batching saves round trips, that confirmation-required actions surface needs_confirmation and require re-sending with confirm: true, and that eval is gated by JEVMCP_ALLOW_JS=1. This enriches readOnlyHint=false and openWorldHint=true without contradicting either.

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 main behavior, round-trip concern, and op reference are packed into a compact front-loaded table with no filler. Each row and caveat earns its place.

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 high-complexity multi-op tool, this is a near-complete manual: all ops, timing defaults, confirmation flow, and the eval gate are covered, and the output schema covers return value details. Minor missing context is the semantics of the four top-level flags, though their names/defaults make them partially self-explanatory.

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%, and the description compensates with a detailed op/fields table covering refs, optional flags, defaults, and value formats. However, the top-level parameters beyond ops (dry_run, session, observe_after, stop_on_error) are not explained beyond their schema names and defaults.

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 first line states a specific verb and object: execute browser operations in order and return a delta observation. The op table makes it clearly an action tool, distinguishable from siblings like browser_observe, browser_tabs, and browser_close.

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 explicit batching advice: 'Batch ops into a single call — each call is a round trip,' so an agent knows to combine operations. It does not explicitly name sibling alternatives or when-not-to-use conditions, though the op table largely implies the tool's scope.

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