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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description is fully consistent with that: 'opens nothing by itself' reinforces the no-side-effect behavior. It goes beyond the annotations by explaining what is actually returned (screens, buttons, fields) and why the tool exists in this instructional form (Appointy's private API is Enterprise-only). What it does not cover is failure behavior, such as what is returned when the appointment cannot be found.

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 key fact — that this returns instructions and opens nothing — is front-loaded and well placed. But two clauses are filler: 'from ChatGPT, Claude or any AI agent' adds no selection value, and the Enterprise-plan note is tangential justification that an agent does not need in order to call the tool. Trimming those would make it a two-sentence 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 zero parameters, no output schema and annotations covering the safety profile, the remaining burden is small, and the description meets most of it by explaining the return format and the required follow-up with browser tools. The one real gap is prerequisites for that follow-up: it never states that the Appointy Cloud Browser must already be open and authenticated.

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 zero parameters, which is the baseline-4 case; there is nothing for the description to disambiguate. The absence of inputs is itself coherent with a tool that only returns instructions rather than acting.

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 specific verb and resource (cancel an appointment in the user's Appointy account) and then clarifies the actual output: step-by-step instructions with screens, buttons and fields. The leading imperative 'Cancel appointment' slightly oversells it as an action tool, but the very next clause ('Returns how to do it ... and opens nothing by itself') corrects that. It distinguishes itself from the cotlet_browser_* tools it hands off to, though it does not differentiate from appointy_reschedule_appointment or appointy_book_appointment.

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 makes the usage sequence explicit: call this to get instructions, then execute with the cotlet_browser_* tools in the Cloud Browser. However, it gives no when-not guidance — nothing says to use appointy_reschedule_appointment instead of cancelling, and no prerequisite is stated (e.g. an existing signed-in browser session). The selection logic is implied rather than spelled out.

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