Run and compare a scenario

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

Beyond the annotations, it discloses two real behavioral traits: results are state-dependent on the starting window/control, and it requires key-press permission. It does not, however, warn that the run writes to the baseline file (the destructiveHint=true side effect), leaving that to the schema's baseline_file/update_baseline text.

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, front-loaded with the purpose and then the critical precondition. Nothing is redundant and no sentence could be dropped without losing meaning.

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 four-parameter tool with an output schema and full schema coverage, the description supplies the essential mental model (regression test, deterministic starting state, permission requirement). The only gap is the baseline-file write behavior, which an agent would otherwise have to infer from the schema.

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 coverage is 100%, so all four parameters, including the nested ScenarioStep fields and the until_speech semantics, are already documented. The description adds the comparative-baseline framing but no extra detail about parameter syntax or interaction beyond the 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 names a specific verb and resource ('run a scenario of key presses and typing') and states the full outcome: recording NVDA speech and focus after each step and diffing against a saved baseline. It explicitly frames itself as 'an accessibility regression test', which separates it from the single-action siblings nvda_press_keys and nvda_type_text.

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 a clear usage condition ('Start from the same place each time... or the results will differ') and a prerequisite ('Needs key presses to be allowed, like nvda_press_keys'). It references the sibling primitives but never explicitly says when to choose this tool over chaining nvda_press_keys/nvda_type_text/nvda_wait_for_speech manually.

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