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

With no annotations, description carries full burden. It discloses auth requirement ('Auth Required + Active'), billing ('per-minute billing from AgentWallet'), and rate limits. Missing explicit mention of side effects like credential expiration or browser lifecycle, but sufficient for safe invocation.

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?

Description is front-loaded with purpose and structured into sections (purpose, install, usage, special case, rate limit). Slightly verbose due to CLI install details, but each sentence serves a purpose.

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 no output schema, the description provides comprehensive context: auth, billing, rate limits, captcha scenario, and post-rental actions. Covers all necessary information for an agent to successfully invoke and handle the 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 100% with one parameter (browser_id) described. Description adds significant value beyond schema by providing CLI install commands and usage examples, guiding the agent on how to use the returned credentials effectively.

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 'Get credentials to rent a real Chrome browser,' specifying the verb (rent) and resource (browser). It distinguishes from sibling tools like search-browsers and list-my-browsers by focusing on the rental action.

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 guidance for when to use (captcha-protected signups via pre-warm-captcha-protected-site prompt) and rate limit handling (429 Retry-After). Does not explicitly state when not to use or mention alternatives, but context is clear for common scenarios.

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