browser_fetch_auth

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

With no annotations, the description carries the full burden. It discloses that the tab is reloaded (a side effect) and that the request is made server-side, and notes the Bearer token limitation. It does not cover failure modes (e.g., no auth tokens found) or return behavior, but the disclosed side effects are significant and useful.

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 sentences, front-loaded with the core purpose, then mechanism, then limitation/example. Every sentence adds distinct value with no waste.

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 tool with 6 params, no annotations, and no output schema, the description explains purpose, mechanism, and a limitation, but omits return format and error scenarios. It is reasonably complete but could benefit from a note on what is returned or what happens on auth capture failure.

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 covers 100% of parameters with descriptions, so the baseline is 3. The description adds no additional parameter-specific meaning beyond what the schema already provides; it only implicitly relates tab and url to the auth capture mechanism.

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 makes an authenticated HTTP request using auth headers captured from a browser tab, distinguishing it from the sibling browser_fetch. It specifies the mechanism (reloading the tab to intercept fresh tokens) and gives an example (Outlook), making purpose 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?

Provides clear context: works for sites using Bearer tokens rather than cookies, and implies it should be used when browser_fetch would not have auth. However, it does not explicitly name browser_fetch as an alternative or state when not to use this tool, so it misses the full when/when-not guidance.

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