enable_proxy_auth

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

With no annotations provided, the description carries the full burden of behavioral disclosure and does so comprehensively. It details side effects ('starts background event listener that auto-terminates after 30s inactivity; initiates pre-warming navigation'), auth requirements ('username and password credentials required'), rate limits ('30-second timeout per inactivity period'), and what the tool returns ('confirmation of proxy auth activation'). This provides rich behavioral context beyond basic functionality.

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 appropriately sized and front-loaded with the core purpose first, followed by important behavioral details. While comprehensive, it could be slightly more concise - some information like the 30-second timeout appears twice (in 'side effects' and 'rate limits'), and the sentence structure is somewhat dense. However, every sentence adds value and there's minimal redundancy.

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 4 parameters, no annotations, and no output schema, the description provides substantial context about behavior, side effects, prerequisites, and usage timing. It covers what the tool does, when to use it, what happens during execution, and what to expect afterward. The main gap is the lack of output schema, but the description does mention what the tool returns ('confirmation of proxy auth activation'), partially compensating for this absence.

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 input schema has 100% description coverage, so the schema already documents all four parameters thoroughly. The description doesn't add any additional parameter-specific information beyond what's in the schema descriptions. According to the scoring rules, when schema_description_coverage is high (>80%), the baseline is 3 even with no param info in the description.

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 specific action ('Activates proxy authentication interception') and resource ('via Fetch domain'), distinguishing it from all sibling tools which are focused on browser automation tasks like navigation, DOM manipulation, or debugging. It precisely defines what the tool does rather than just restating the name.

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 description provides explicit guidance on when to use this tool ('Use this after "restart_chrome" with proxy settings') and mentions alternatives ('manual proxy configuration in system settings'). It also specifies prerequisites ('Chrome must be started with proxy-server flag'), giving clear context for proper usage.

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