Run scenarios

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

Annotations declare readOnlyHint=false and destructiveHint=false, so the safety profile is already carried; the description usefully adds what the run produces (per-step results, runtime errors, captures, final state). It does not disclose the write side effect implied by accepting captures as baselines, leaving a behavioral gap.

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 sentences, no filler, and the primary action plus default scope are front-loaded ahead of the return-value summary. Every clause 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 no-required-param tool with no output schema, naming the returned artifacts is helpful, but the definition omits sibling routing (run_tests, fuzz) and the consequences of the update/baseline path. Adequate but with clear gaps.

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 all three parameters are already documented in the schema. The description only echoes the files default ('or the given files') and adds nothing about root or update semantics.

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?

Specific verb+resource: runs scenarios/*.json files in a headless browser, with scope made explicit ('or the given files'). It doesn't differentiate itself from likely siblings such as run_tests or fuzz, so the agent must infer which 'run' tool applies.

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 when-to-use guidance or conditions for choosing this over run_tests/fuzz/game_replay. The description only defines file scope ('scenarios/*.json', default all), which is not the same as telling the agent when this tool is the right one.

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