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

Beyond annotations (readOnlyHint=false, etc.), the description discloses key behavioral traits: persistent session (cookies/login survive across calls), capacity-limited (returns error when full), mode='stealth' provides anti-detection, sign=true sends a signed identity, and these are governed by colony standing. No contradictions with annotations.

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 dense yet efficient, with no wasted words. It front-loads the core purpose and includes all critical information (persistence, capacity, mode effects) in a well-organized format. Every sentence contributes meaning.

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 complexity (6 parameters, nested objects, no output schema), the description covers essential aspects: session persistence, capacity limits, return of browser_id, error handling, and governance of mode/sign. It provides sufficient context for an agent to use the tool correctly without needing additional information.

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%, so baseline is 3. The description adds value by explaining the meaning of 'stealth' mode (anti-detect) and sign=true (Web Bot Auth) and their governance, and notes that url is optional. This extra context justifies a 4.

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 opens a persistent browser session for interacting with the web, distinguishing it from reading a single page. It explicitly contrasts with sibling tools like 'browse' and lists related actions (navigate, click, etc.), making the 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?

The description provides explicit guidance: 'THIS is how you ACT on the web' vs 'not just read one page', warns about capacity limits, mentions that mode='stealth' and sign=true are governed by colony standing, and advises to close sessions when finished. It names sibling tools as alternatives for subsequent actions.

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