Open URL

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

The description discloses several important behaviors beyond the annotations: automatic https:// prefixing, waiting for navigation to complete, the possibility that dynamic content may still load, and error propagation through @handle_sb_errors. These details materially help an agent predict what will happen during invocation and what to do about incomplete loading.

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 and front-loaded with the primary behavior, then provides examples, return details, and routing guidance in compact sections. Even the longer protocol-defaulting sentence earns its place because it changes how the parameter should be supplied. There is minimal redundancy given the amount of useful context.

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?

With a single parameter and an output schema already present, the description covers everything an agent needs: parameter format, protocol normalization, navigation completion semantics, synchronization guidance, error behavior, return value, and explicit routing to sibling tools. No important invocation question is left unaddressed.

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?

The schema provides zero description for the url parameter, so the description carries the full burden. It fully compensates by defining the parameter in the Args section, explaining that it accepts either a complete URL or a bare hostname, and noting the automatic protocol prefixing behavior with a concrete example.

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 opens with a specific, actionable statement: 'Navigate the current browser tab to the URL provided.' It clearly distinguishes open_url from manage_history by explicitly matching 'navigate to a new URL' to this tool and all history-based navigation to manage_history. The verb, resource, and behavioral scope are unambiguous.

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 'Tool selection' section explicitly states when to use open_url versus manage_history for back, forward, and reload actions. It also advises using wait_for_condition when synchronization with dynamic content is required, giving clear context about limitations and alternatives.

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