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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, so the safety profile is covered. The description adds genuinely new facts: it is free and opens no browser session, which matters for an agent deciding whether calling it costs a session. It does not say whether guidance is cached or regenerated per call.

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 content is packed into a single long sentence chain, so key routing information ('Call it before the first browser step') is buried mid-text rather than front-loaded. It is dense but mostly earns its words; restructuring into two or three short sentences would improve scannability.

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 two-parameter, read-only guidance tool with no output schema, the description enumerates what the answer contains (browser choice, sign-in link, method, screens, notes, dedicated tools) well enough for an agent to know it can rely on the result. Only the freshness/workspace-scoping of the guidance is left unstated.

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% and both parameters (app name/slug with a Campaign Monitor default, and the user's task in their own words) are fully documented in the schema. The description hints that the app drives which browser and sign-in link are returned, but adds no format or syntax detail beyond that, so the 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 states a specific resource and what it returns: browser choice and sign-in link for the workspace, step-by-step method, app screens/menus/actions, and dedicated tools. It is clearly distinguished from the cotlet_browser_* siblings, which perform steps rather than explain how. It loses a point only because the opening clause 'How to work in an app' largely restates the title before the substance arrives.

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' gives an explicit ordering instruction relative to the browser tools, and 'Works for any web app; one outside Cotlet's catalog gets the general method' covers the fallback case. There is no explicit when-not, but the pre-step rule implicitly excludes mid-task consultation.

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