firefox_open_tab

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

Annotations already declare readOnlyHint=false, openWorldHint=true and destructiveHint=true, so the safety profile is covered. The description adds one genuinely new behavior: redirects to unauthorized origins are blocked. It does not explain what "authorized" means, how authorization is obtained, or why an open-tab action carries a destructive hint.

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?

Two short sentences, front-loaded with the action and followed immediately by the constraint; no filler. It is perhaps overly terse given the undocumented second parameter, but nothing is wasted.

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?

There is no output schema and no mention of what is returned (e.g., a tab identifier) for a tool whose output would be needed by sibling tools like firefox_release_tab or firefox_tab_action. The authorization prerequisite and the meaning of the `active` flag are also unaddressed, so this is only minimally complete for a two-parameter state-changing tool.

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 only 50%: url is documented in the schema, but the boolean `active` parameter is undocumented in both schema and description. The description adds no meaning about what `active` controls (e.g., whether the new tab takes focus), so it fails to compensate for the coverage gap.

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?

States a specific verb and resource ("Open an authorized HTTP/HTTPS URL in a new tab") and adds a scope constraint. It implicitly distinguishes itself from firefox_navigate (existing tab) and firefox_tab_action, but never names an alternative, so differentiation is inferred rather than stated.

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?

"Open ... in a new tab" implies the use case versus navigating an existing tab, and "authorized" hints that a prior access grant (likely via firefox_request_access) is required. Neither the when-to-use condition nor the prerequisite step is stated explicitly, leaving the agent to infer both.

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