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

'opens nothing by itself' directly confirms the readOnly/idempotent/non-destructive annotations and forecloses the assumption that calling this creates an invoice. It also discloses the API-key approval gate with a checked date, which is useful context beyond the annotations. Return format is only loosely described (screens, buttons, fields).

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 two-clause sentence is front-loaded and earns its place, but the trailing API-key aside with a date is tangential to invoking this tool and lengthens the definition without changing the call. Some phrasing ('from ChatGPT, Claude or any AI agent') is filler.

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 params and no output schema, the description carries the burden of explaining what comes back, and it does so at a high level (step-by-step screens, buttons, fields). Combined with the clear handoff to browser tools, an agent has enough to call it and act on the result.

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?

Zero parameters, so there is nothing for the description to disambiguate; baseline applies. It implicitly signals that account targeting happens elsewhere (the user's own account), which is a small extra.

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 verb and resource (create an invoice in the user's Markate account) and immediately clarifies the twist: it returns step-by-step instructions rather than performing the action. That clarification disambiguates the misleading 'create' name, though it does not distinguish this tool from guide-style siblings such as 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 tells the agent what to do next (perform the flow with cotlet_browser_* tools in the Markate Cloud Browser) and hints that the official API route requires an approved key. It does not explicitly say when to use this instead of a plain app guide or the API, and gives no exclusions.

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