open_tab

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

With no annotations, the description carries the behavioral burden and does so well: it discloses that a new tab is created, an id is returned, activate controls foreground/background placement, and wait_for_load blocks until the document finishes loading. This goes beyond the bare operation implied by the tool name.

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 front-loaded with the core behavior and return value, followed by a compact, clearly labeled Args list. Every sentence earns its place; there is no filler or redundant restatement of the tool name.

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?

For a simple three-parameter browser tool, the description is complete: it states the required URL, explains both optional booleans, and names the return value, while an output schema exists for the exact return structure. Error handling is not described, but it is not essential for correct invocation here.

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 no property descriptions (0% coverage), but the description's Args section documents all three parameters: url requires an absolute URL, activate means 'bring to front,' and wait_for_load means wait for document load. The description fully compensates for the missing schema-level parameter semantics.

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 states a specific verb-resource pair: 'Open a URL in a new tab and return its id.' This clearly distinguishes it from sibling tools like navigate (implied current tab), activate_tab, and close_tab, and includes the key return value.

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?

Usage is implied by the action itself: use this when you want to open a URL in a new tab. However, the description gives no explicit guidance about when to prefer open_tab over navigate, activate_tab, or other siblings, and offers no exclusions or alternative conditions.

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