browser_explain_last_action

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

No annotations are provided, so the description carries the full burden. It discloses that the tool uses a recorded temporal timeline, linking to network requests, console errors, and DOM mutations. It does not mention side effects, rate limits, or auth needs, but given the read-only nature, the description is transparent enough.

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 highly concise, consisting of two sentences plus a usage directive. It front-loads key terms ('CAUSAL EXPLAINABILITY') and avoids redundancy. Every sentence serves a purpose.

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 the tool's low complexity (one optional parameter, no output schema), the description adequately covers its behavior and use case. It explains what the tool links to (network requests, console errors, DOM mutations) but does not describe the output format, which could be helpful.

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% for the single parameter `windowMs`, with a description provided. The tool description does not add further meaning beyond what the schema already states. Baseline 3 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 specifies the tool's purpose: explaining why the page is in its current state by linking recent actions to network requests, console errors, and DOM mutations. It uses specific verbs and resources (e.g., 'explain', 'causal', 'temporal timeline') and distinguishes itself from snapshot-based tools, though it does not name specific siblings.

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 explicitly states when to use the tool: 'Call this right after an action that behaved unexpectedly.' This provides clear context for invocation. However, it does not explicitly mention when not to use it or suggest alternative tools for expected behaviors, leaving some gap in coverage.

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