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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true and openWorldHint=false, and the description reinforces this with the important disclosure that the tool 'opens nothing by itself.' It adds meaningful context beyond annotations: the return shape (screens, buttons, fields) and the absence of a public API or developer docs. Rate limits or auth requirements are not mentioned, keeping it below a 5.

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 action and its disambiguation are front-loaded, and the follow-up workflow is stated in one compact sentence. Minor deductions for the awkward trailing fragment 'TrueCoach's official API:' which reads as an incomplete heading and slightly disrupts flow.

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 guide tool with no output schema, the description covers what it returns (step-by-step instructions with screens, buttons, fields), that it performs no action, and the follow-up execution path. That is sufficient for correct invocation; only finer return-format or error-handling detail is absent.

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 is 4 and there is nothing for the description to disambiguate. The empty schema is fully self-explanatory and the description correctly adds no parameter detail where 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 names a specific resource (TrueCoach client messaging) and explicitly corrects the potential misreading of the name by stating it 'returns how to do it in TrueCoach step by step' rather than performing the action. It distinguishes itself from the cotlet_browser_* siblings by naming them as the tools that actually execute the workflow, though the opening verb 'Message client' creates some initial tension that only later sentences resolve.

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 clearly states the usage chain: call this tool to get the step-by-step guide, then execute with the cotlet_browser_* tools in the TrueCoach Cloud Browser. It also notes there is no official API, which explains why the browser route is required. It stops short of stating explicit exclusions or when-not-to-use conditions.

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