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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds non-obvious operational context: the call is free and starts no browser session, and an uncataloged app still yields a general method rather than failing. It doesn't say how large the returned guidance is, but nothing contradicts the 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 purpose and the invocation rule are front-loaded, and the trailing 'Free, no browser session' is a useful qualifier rather than filler. The middle sentence is a long comma-run list, which is dense but every item describes real returned content, so little could be cut without losing information.

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?

There is no output schema, so the description carries the return-value burden and does so by enumerating the guidance contents (browser, sign-in link, method, screens/menus/actions, notes, app tools). Combined with the explicit trigger and fallback behavior, an agent has everything needed to call this correctly before its first browser step.

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 both parameters documented, including the Mews default and the 500-character task phrasing, so the baseline is 3. The description only loosely gestures at the parameters ('in an app', 'what the user wants done') and adds no format or resolution guidance beyond the schema, e.g. how a slug differs from a display name.

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 states a concrete resource (guidance for working inside a specific web app via the Cloud Browser) and enumerates what it returns: browser choice, sign-in link, step-by-step method, screens/menus/actions, notes, and dedicated app tools. It is clearly a knowledge/instruction tool rather than an action tool, which separates it from the cotlet_browser_* siblings, though it never names those siblings directly.

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 an explicit trigger ('Call it before the first browser step in an app') plus scope ('Works for any web app') and a defined fallback ('one outside Cotlet's catalog gets the general method'). An agent knows exactly when to invoke it and what happens for an unknown app.

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