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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's job is to add operational context — and it does: "Free, no browser session" tells the agent this costs nothing and opens no session, which is material before a sequence of browser calls. It does not say how large the returned guidance is or whether it must be re-fetched per app, but the added value is real.

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 trigger condition is front-loaded in the first content sentence after the lead clause, and every clause carries information (return contents, timing, universality, cost). The middle enumeration ("the app's screens, menus and actions, notes, and the app's dedicated tools") is a long comma run that is harder to scan than a short list, but no sentence is 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?

For a zero-required-parameter guidance tool with no output schema, the description covers what the agent needs: when to call it, what it returns, that it works outside the catalog, and that it is free and session-free. It does not clarify whether the returned method should be followed verbatim or whether it should be re-called when the task changes mid-session, a minor remaining gap.

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% — both `app` (name or Cotlet slug, default Postscript) and `task` (user's words) are fully documented in the schema. The description mentions the app context only indirectly ("which browser to use for this workspace") and says nothing about how the free-text `task` shapes the returned method, so it adds no meaning beyond the schema. Baseline 3 applies.

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 enumerates concretely what the tool returns: which browser to use for the workspace, the sign-in link, the step-by-step method, the app's screens/menus/actions, notes, and the app's dedicated tools. That separates it from the cotlet_browser_* siblings, which perform actions rather than explain how to. It loses a point only because the opening is a noun phrase rather than an explicit verb stating what the call produces.

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?

"Call it before the first browser step in an app" is an explicit, actionable trigger condition, and "Works for any web app; one outside Cotlet's catalog gets the general method" scopes coverage. It does not name an alternative for the adjacent case (e.g., using cotlet_apps to discover the slug first), so it stops short of full when/when-not guidance.

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