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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, not open-world), and the description adds real value beyond them: it does not touch the live account, it returns screen/button/field-level instructions, and it notes the official API is Pro-plan-only and narrow. That last sentence is cryptic in phrasing but signals why the browser path exists.

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 message arrives early, but the third sentence ('ManyChat's official API: Yes, but only on the Pro plan or higher, and it is narrow') is a fragment with no clear antecedent and reads like leftover research notes. It costs space without giving the agent an actionable rule.

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 zero-parameter guidance tool with no output schema, the description covers what it returns (screens, buttons, fields), what it does not do (open or modify anything), and how to act on the result. The only gap is that the shape of the returned guidance is not described beyond a short parenthetical.

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, so there is nothing for the description to disambiguate; the baseline for a no-parameter tool is 4. The description correctly implies no input is needed before returning guidance.

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 resource (broadcasts) in the user's own ManyChat account and, crucially, clarifies that the tool returns step-by-step guidance rather than data. That resolves the tension with the name 'list_broadcasts', which would otherwise read as a data-retrieval call. It lacks an explicit contrast with manychat_send_broadcast or manychat_list_contacts, so sibling differentiation is only partial.

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 states the immediate next action clearly: 'then do it with the cotlet_browser_* tools in the user's ManyChat Cloud Browser', which tells the agent how this tool fits into a workflow. It also sets a negative expectation ('opens nothing by itself'). No explicit when-not-to-use condition is given, keeping it below a 5.

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