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

Beyond the annotations (readOnly, idempotent, non-destructive, closed-world), the description discloses the return shape – step-by-step screens, buttons and fields – and explicitly states the tool opens nothing itself, which prevents a wrong expectation of live data. The note that Mailshake has a REST API but no official MCP server usefully rules out an alternative route.

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 key operational fact (returns instructions, browser tools do the work) is buried in the middle of the first paragraph rather than front-loaded. "from ChatGPT, Claude or any AI agent" is promotional filler, and the API/MCP-server paragraph, while relevant, is long for a supporting note.

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, that it performs no side effects, and which tool family to use next. What is missing is a concrete statement of how the returned steps are consumed and whether a Mailshake account/session must already exist.

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 the baseline applies; there is no parameter meaning to add or miss. The description's opening "user's own Mailshake account" does imply an implicit account-scoping the schema cannot express, which is mildly useful 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?

The name and title say "List campaigns," but the description reveals the tool does not list anything itself – it returns a step-by-step how-to for a human/agent to follow in the browser. The clarifying clause ("Returns how to do it in Mailshake step by step ... and opens nothing by itself") rescues it, but the leading verb points at the wrong outcome, and no sibling Mailshake tool is named to differentiate scope.

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 does state the follow-up path explicitly ("then do it with the cotlet_browser_* tools in the user's Mailshake Cloud Browser"), which is real when-to-use guidance for a guide-style tool. There is no statement of when not to use it, no prerequisite checks (account connected, signed in), and the API note is informational rather than directive.

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