chrome_startup_summary

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

Discloses read-only nature and explains conditions for empty results when trace starts after launch. With no annotations, description provides full behavioral context.

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?

Concise with bullet points, every sentence adds value. No unnecessary words, and structure facilitates quick understanding.

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?

Completely covers purpose, usage, limitations, and edge cases for a simple tool with no parameters or output schema. Nothing missing given the context.

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?

No parameters exist, and description confirms 'Parameters: none — operates on the loaded trace.' While schema coverage is 100%, description adds no beyond but is clear.

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?

Clearly states the tool summarizes Chrome browser startup events with specific fields listed. Distinguishes from siblings like chrome_main_thread_hotspots by targeting 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?

Provides explicit use cases (measuring time-to-first-visible-content, comparing launch causes) and clearly states when not to use (non-Chrome traces, steady-state browsing with explicit alternative).

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