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

Annotations already declare readOnlyHint=true and destructiveHint=false, but the key behavioral fact — that this tool performs no action itself and only returns procedural guidance — is stated in the description ('opens nothing by itself'), which the annotations alone would not convey. It also dates the API claim ('checked 22 Oct 2026'), signaling possible staleness. No pagination/return-size detail, so 4.

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 first two sentences are front-loaded and earn their place. The trailing paragraph about Constant Contact's v3 REST API and beta MCP server is tangential to invoking this specific tool and adds length without changing how an agent calls it.

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 and no output schema, the description carries the burden and does state what is returned (step-by-step screens, buttons, fields) plus the required follow-up tooling. It does not say how prerequisites (browser session, login state) are handled, which is the main remaining gap for a guidance-plus-browser workflow.

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 for a 0-param tool is 4. No parameter-related gaps exist.

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 ('Schedule email in the user's own Constant Contact account') and then corrects the implied impression by stating it 'Returns how to do it in Constant Contact step by step (screens, buttons, fields) and opens nothing by itself.' That distinguishes it from the sibling constant_contact_* tools that perform real actions. The first sentence alone would be misleading, so it is a 4 rather than a 5.

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 explicit sequencing: call this to get the steps, then execute them with the cotlet_browser_* tools in the Cloud Browser, and it flags that an official REST API/MCP server exists as an alternative path. It stops short of explicit when-not-to-use conditions (e.g. if the user is already in the browser session), so it is not a full 5.

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