Perform actions

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

With no annotations, the description carries full burden, and it does disclose two real behavioral traits: no retry/healing on failure and per-action ok/error/timing results. It omits whether execution halts on the first error versus continuing through the remaining actions, and says nothing about what page state the actions mutate.

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?

Three clipped sentences, no filler, with the action list front-loaded ahead of the failure-mode caveat and the return shape. Every sentence carries 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?

No output schema exists, and the description does cover the return shape (per-action ok/error/timing), which is the most valuable thing it adds. However, for a mutation-heavy execution primitive with zero annotations, the meaning of stage_id and the error-handling policy (stop vs continue) are left unaddressed.

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% at the top level: stage_id is completely undefined in both schema and description, and timeout_ms has no explanation. The description restates the action type enum already present in the schema, so it adds almost nothing beyond structured fields for the parameters that genuinely need explanation.

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 (execute) and resource (an ordered list of click/fill/press/hover/select/scroll actions) scoped to a stage, which clearly separates it from capture, wait_for, and measure. It does not name a sibling it differs from, so sibling differentiation is implicit rather than explicit.

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 extra steps, no retries, no healing" implies this is the raw low-level primitive, contrasted implicitly with the higher-level scenario_run sibling, but the description never says when to prefer one over the other or what prerequisites apply. Usage is inferable, not stated.

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