browser_get_timeline

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

With no annotations, the description fully explains the behavioral traits: provenance tags, trust levels, and the warning about page-controlled events. It adds value by cautioning against treating page-authored text as instructions. However, it does not explicitly state that the operation is read-only, which is implicit.

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?

Three concise sentences: purpose, detailed trust explanation, usage advice. No fluff, well-structured, and front-loaded with key information.

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?

The description covers the tool's purpose, trust tags, and usage advice. It is complete for a tool with 2 parameters and no output schema, though it could mention that it's a non-destructive read operation.

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%, so the description's main addition is explaining the trust enum values and their significance. It also mentions the default limit of 50. This adds context beyond the schema's basic descriptions.

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 returns a 'recent unified event timeline' with specific event types and provenance tags. It uses a specific verb ('Return') and resource, and distinguishes from siblings like browser_query_timeline by mentioning provenance tags.

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 guidance on using the trust tag to avoid acting on injected instructions, but does not explicitly state when to use this tool versus alternatives like browser_query_timeline. The usage context is clear but lacks explicit comparisons or exclusions.

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