chrome_startup_summary

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

The description declares it is read-only and explains the empty result scenario (trace started after launch). While no annotations are present, this covers the main behavioral traits for a query tool. It could mention that it does not modify state, but the read-only statement suffices.

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 well-structured with a clear header, bullet-style guidelines, and notes. It is slightly verbose but no words are wasted. Most sentences add value.

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 no output schema, the description lists the returned fields and explains empty results. It covers the tool's scope and limitations. It could mention the expected number of rows or format, but overall it is adequately complete.

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 zero parameters and schema coverage is 100%. The description adds context that the tool operates on the loaded trace, which is useful but not required. According to guidelines, baseline 4 applies.

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 it summarizes Chrome browser startup events with explicit fields (id, name, launch_cause, etc.). It distinguishes itself from siblings like chrome_main_thread_hotspots and chrome_page_load_summary by focusing on startup events.

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?

The description provides explicit use cases ('when: measuring time-to-first-visible-content...') and anti-use cases ('Don't use for: non-Chrome traces...'). It also names an alternative sibling (chrome_main_thread_hotspots) for steady-state work.

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