new_page

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

Description lacks behavioral details beyond the basic action. Annotations indicate readOnlyHint=false, but description doesn't mention if the new tab becomes active, error handling for invalid URLs, or whether it requires user interaction. For a mutation tool, more context is needed.

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?

Very concise single sentence stating the core action. However, it could front-load the return value ('Returns tab index') more prominently, and add a brief usage note without losing conciseness.

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 simplicity (1 parameter, no nested objects), the description is mostly adequate. It notes the return value (tab index). However, it misses behavioral nuances like focus behavior or whether the URL is validated.

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% with description 'Target URL'. The tool description adds minimal meaning ('Open new tab at URL'), which slightly reinforces but doesn't exceed the schema. 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?

Description clearly states the action (open new tab), the resource (new tab), and the parameter (URL). It distinguishes from siblings like 'navigate_page' which navigates the current page, and 'select_page' which switches tabs.

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?

No guidance on when to use this tool versus alternatives. For instance, it doesn't clarify that this creates a new tab while 'navigate_page' changes the current page, or preconditions like page load status.

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