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

Adds context beyond the annotations: this is a real Chrome session already authenticated as the user, it is restricted to BrightLocal pages, and it returns the visible page elements and text with stable reference numbers (important since there is no output schema). The phrase 'with the same numbers' is opaque and the description does not mention session lifetime or cleanup (cotlet_browser_close) for a non-idempotent operation.

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 tight sentences, front-loaded with the action and the imperative 'Call it first.' No redundant restatement of the title or schema, and no filler.

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 one optional parameter, no output schema, and annotations already covering the safety profile, the description covers authentication state, URL restriction, and return shape. It omits session persistence/cleanup and error behavior, which are the remaining things an agent would need for reliable orchestration.

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 the baseline is 3; the description earns above that by adding a real constraint the schema lacks — only BrightLocal pages may be opened, despite the schema describing a generic public http/https URI. It stops short of saying what happens if a non-BrightLocal URL is passed.

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: starts the user's BrightLocal Cloud Browser (real Chrome on Cotlet, signed in as the user) and opens `url`. The parenthetical scopes it against BrightLocal native tools, but it never distinguishes itself from the sibling cotlet_browser_navigate, which an agent could easily mistake for the same 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?

Gives explicit sequencing ('Call it first') and an explicit boundary ('use it for what the BrightLocal tools do not cover'). It does not name cotlet_browser_navigate or cotlet_browser_close as alternatives, so the when-not case for overlapping browser siblings is left to inference.

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