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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, and the description is consistent with them by stating it 'opens nothing by itself'. It adds useful behavior detail (returns screens, buttons and fields rather than data), but the closing paragraph about Bokio's official REST API, price plans, and OAuth token types has no bearing on invoking this zero-parameter guide tool and does not say whether an active Cloud Browser session is required.

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 sentence is front-loaded and useful, but roughly half the text is an unrelated aside about Bokio's public API, plan limits and OAuth integration models that does not help an agent call this tool. That filler dilutes an otherwise short definition.

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 does carry the burden of describing returns, and it partially does ('how to do it in Bokio step by step (screens, buttons, fields)'). However, it never states the shape of that output or any preconditions such as an open Cloud Browser session, and the API/OAuth paragraph adds length without filling those gaps.

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?

The tool takes no parameters and the schema coverage is 100%, so there is nothing for the description to disambiguate. Baseline 4 applies for a parameterless 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 description names the resource (unpaid invoices in the user's Bokio account) but immediately redefines the action: it does not list invoices, it returns step-by-step instructions for doing so manually. That caveat is valuable, yet it conflicts with the plain reading of the name, so an agent must read carefully to learn the tool produces guidance rather than invoice data. No differentiation from the bokio_* siblings is offered.

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 implies when to use it (user wants unpaid invoices in Bokio) and points to the follow-up path: execute the steps with the cotlet_browser_* tools. There is no explicit when-not or comparison against alternatives such as a hypothetical direct-listing tool, leaving routing partially inferred.

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