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

Adds meaningful context beyond annotations: it emphasizes 'opens nothing by itself' and returns screens/buttons/fields instructions, consistent with readOnlyHint=true, idempotentHint=true, and openWorldHint=false. It also discloses that Mailshake has a REST API but no official MCP server, explaining why the browser-driven approach exists, though it doesn't describe the return content structure.

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 purpose is front-loaded and the workflow is clear. However, the closing sentence about Mailshake's API and the dated 'checked 22 Oct 2026' note is tangential filler that distracts from the actionable workflow and dilutes concision.

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, informational tool it covers the essentials, but it never states what the returned instructions look like or what to do if the user has no Mailshake Cloud Browser session. The API aside contributes little to actually invoking the tool 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?

With zero parameters, the baseline is 4; there are no parameter semantics to explain. The description doesn't clarify how the target campaign is identified, which the agent must infer from browser context.

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?

States a specific verb and resource: adds a follow-up to a campaign in the user's own Mailshake account. It is distinguishable from siblings by its object (follow-up) and by the explicit note that it only returns instructions, though it doesn't contrast with other campaign-mutation siblings beyond the object name.

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?

Gives a clear two-step workflow: first call this to get step-by-step instruction, then execute with cotlet_browser_* tools in the user's Mailshake Cloud Browser. It names the alternative tool family explicitly. It lacks explicit when-not conditions or prerequisites such as needing an existing campaign or browser session.

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