chrome_scroll_jank_summary

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

The description discloses that the tool is read-only, operates on the loaded trace, returns limited rows sorted by delay descending, and explains empty result behavior. No annotations are provided, so the description fully carries the behavioral disclosure burden.

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 main purpose and output fields, followed by usage guidance and alternatives. It is slightly longer than necessary but every sentence adds value. A bit more conciseness could improve it.

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?

Given zero parameters and no output schema, the description covers the essential aspects: purpose, usage, alternatives, and empty result behavior. It could briefly explain the output fields more, but for a simple query tool it is adequate.

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?

There are no parameters, and the input schema is empty. The description explicitly states 'Parameters: none — operates on the loaded trace,' which adds clarity. Per the guidelines, zero parameters give a baseline of 4, which is appropriate.

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 clearly states the tool's purpose: 'Summarize the worst scroll jank frames in a Chrome trace' and lists the output fields. It distinguishes from sibling tools like execute_sql by noting it is preferred over hand-rolling SQL and is limited to Chrome traces.

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?

Explicit guidance: 'Use when: investigating jank reports, finding scroll regressions, ranking jank causes. Don't use for: non-Chrome traces. For per-frame causes outside the top 100, drop to execute_sql.' This covers when to use, when not to, and an alternative.

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