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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and the description is consistent with that by stating it "opens nothing by itself." It adds genuinely useful context beyond the annotations: the return is step-by-step UI instructions, and the note about the narrow official MCP server explains why this tool 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?

Three sentences, front-loaded with the action, which is good. The closing sentence about ClickSend's REST API and narrow official MCP server is tangential justification rather than call guidance, and the imperative opening conflicts with the later "opens nothing by itself," costing clarity.

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 parameters, no output schema, and annotations covering the safety profile, the description supplies what an agent needs: what it returns (step-by-step screens/buttons/fields) and what to do next (cotlet_browser_* tools). It could say more about prerequisites, such as needing a logged-in Cloud Browser session.

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. Baseline of 4 applies.

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 makes clear this is a guidance tool: it "Returns how to do it in ClickSend step by step (screens, buttons, fields) and opens nothing by itself." That distinguishes it from the actual browser-mutation siblings. The leading imperative ("Remove duplicate contacts...") momentarily reads as if the tool performs the removal, which slightly muddies the verb.

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 next step: use the cotlet_browser_* tools in the user's ClickSend Cloud Browser to carry out the steps. However, it gives no when-not guidance and does not differentiate from the adjacent sibling clicksend_remove_opted_out_contacts or explain when this approach beats calling ClickSend's API directly.

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