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

Annotations already declare readOnly, idempotent, non-destructive and openWorld=false, so the safety profile is covered. The description still adds real context beyond them: the tool opens nothing by itself, returns a screen/button/field walkthrough, and requires handoff to the browser tools. It omits how long the returned guide is or whether it varies by plan/edition.

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 front-loaded claim ("List customers") is the least accurate part, and the actual behavior surfaces only in the second clause. The API footnote ("checked 11 Oct 2026") is a dated aside that does not help an agent decide anything, though the rest is compact.

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 must explain the return value, and it does: a step-by-step Yardbook walkthrough. It also explains why browsing is necessary (no public API). It could have said whether the returned steps are guaranteed to match the user's Yardbook version.

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?

There are zero parameters, so the baseline is 4; there is nothing for the description to disambiguate. The empty schema with additionalProperties=false is consistent with a no-argument guide tool.

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 opening clause says it will "List customers," but the tool actually "Returns how to do it in Yardbook step by step" — a guide, not a data fetch. That core fact is stated, yet it is in tension with the name and first sentence, so an agent skimming could expect customer records. It distinguishes itself from the browser tools but never contrasts itself with the closest sibling, cotlet_app_guide.

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?

It gives a clear sequencing rule: call this first, then act via cotlet_browser_* inside the Yardbook Cloud Browser. It offers no guidance on when this is preferable to other Yardbook tools (e.g., list_unpaid_invoices) or on any preconditions such as an authenticated session.

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