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

The annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description adds genuinely new behavioral context: the tool opens nothing, returns procedural instructions rather than data, and requires a follow-up browser session to effect the change. It does not describe the shape or length of the returned steps, but the key non-obvious trait is disclosed and nothing contradicts the annotations.

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 facts — returns steps, opens nothing, then use the browser tools — are front-loaded and useful. The trailing sentence about Mautic's REST API and the absence of an official MCP server is tangential justification, and the parenthetical "checked 23 Oct 2026" is noise that does not help an agent decide or invoke. Tightening to two sentences would lose nothing.

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, read-only guidance tool with no output schema, the description covers what matters: what it returns (screens, buttons, fields), what it does not do (opens nothing), and how to complete the task afterward. Minor gaps remain, such as prerequisites on the user's Mautic account or what happens if the target contact is not already identified, but the definition is sufficient to invoke correctly.

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 and the schema is an empty closed object, so there is nothing for the description to disambiguate. Baseline 4 applies; the description adds no parameter detail because none is needed.

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, not an action tool: it "returns how to do it in Mautic step by step (screens, buttons, fields) and opens nothing by itself." That resolves the mismatch implied by the name "Set Do Not Contact" and separates it from the cotlet_browser_* siblings that actually perform the change. It stops short of naming a specific Mautic alternative, but the resource and output are unambiguous.

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 workflow: call this to get the steps, then execute them with the cotlet_browser_* tools in the Mautic Cloud Browser. That is explicit routing to the correct alternative. It does not state any when-not-to-use condition (e.g. when a direct API-backed sibling should be preferred), so it falls just short of full guidance.

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