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 genuinely non-structured facts: it is free, opens no browser session, and degrades gracefully (general method) for apps outside the catalog. It does not describe how much content comes back or whether it is cached, which keeps it at 4.

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 core instruction ('Call it before the first browser step in an app') is front-loaded, and the enumerated payload follows efficiently. It reads as one long run-on sentence with a trailing app-specific action list that is long but does convey concrete coverage for the one catalogued app.

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?

With no output schema, the description carries the burden of explaining what comes back, and it does: browser choice, sign-in link, method, UI structure, notes, and dedicated tools. It also covers cost (free, no session) and the out-of-catalog fallback, which are the main unknowns an agent would have before deciding to call it.

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 description coverage is 100% and both parameters (app, task) are documented in the schema, including the Nextdoor default, so the baseline is 3. The description hints that output is tailored to the app and task ('the method step by step', per-app actions), but adds no format, granularity, or fallback detail beyond what the schema states.

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 uses a specific verb-and-resource framing ('How to work in an app... with Cotlet's browser tools') and then enumerates exactly what the guide supplies: which browser for the workspace, the sign-in link, the step-by-step method, screens, menus, actions, notes, and dedicated tools. That clearly separates it from the action siblings (cotlet_browser_click, nextdoor_create_post) which perform work rather than explain it.

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 trigger condition, and 'Works for any web app; one outside Cotlet's catalog gets the general method' scopes applicability. It stops short of naming an alternative or a when-not-to-use case (e.g., once you already have the method, or how it differs from cotlet_apps for catalog listing), so it is clear context without exclusions.

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