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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely new operational facts: it is free, consumes no browser session, and degrades gracefully to a general method for apps outside the catalog. Return shape is not described, but annotations and the tool's advisory nature lower that burden.

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 is front-loaded in the first clause, but the sentence then becomes a long comma-chained inventory of guide contents that an agent does not strictly need to make the call. The MassageBook action list is useful specificity but sits awkwardly at the end, after the general applicability claim.

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 read-only advisory tool with two optional, fully documented parameters, no output schema, and complete annotations, the definition covers purpose, trigger timing, cost, and fallback behavior adequately. The only meaningful omission is guidance on how its output relates to the dedicated massagebook_* tools.

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 name/slug with a MassageBook default, and the user's task in their own words) are already documented in the schema. The description reinforces the default app and the MassageBook action coverage but adds no syntax, format, or interpretation guidance beyond the schema, 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 names a concrete resource (a how-to guide for operating a specific web app via Cotlet's browser tools) and enumerates what the guide contains: browser choice, sign-in link, step-by-step method, screens/menus/actions, notes, and dedicated tools. It stops short of explicitly distinguishing itself from cotlet_apps (the catalog) or the massagebook_* action tools, so an agent must infer the boundary.

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 a clear trigger, and "Works for any web app; one outside Cotlet's catalog gets the general method" sets expectations for uncataloged apps. It does not explicitly say when to prefer the dedicated massagebook_* tools over clicking through the browser, which is the main sibling-routing decision an agent faces here.

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