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

Annotations already declare readOnly/idempotent/non-destructive and openWorldHint=false, so safety is covered structurally. The description adds real value beyond that: it states the tool takes no input and clarifies that no actual sign-up occurs, which prevents the agent from treating it as a transactional action. It does not describe response format in detail, but it does enumerate the content delivered.

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?

Three short sentences, front-loaded with the scope and content of the answer, then the usage cue, then the no-input constraint. Minor redundancy between the title-like opening and the usage line keeps it from being maximally tight, but nothing is wasteful.

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 no output schema, the description compensates by listing what the answer contains (steps, payment timing, review time, shipping, start link), which is the key thing an agent needs to decide whether this tool answers a given user question. Adequate for a zero-parameter informational tool; only a minor gap on how the link should be presented.

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?

There are zero parameters, which is the baseline-4 case. The description reinforces this by explicitly stating 'takes no input', so the agent will not attempt to pass arguments.

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 the specific content the tool returns: the four onboarding steps, payment timing, review time, shipping, and the start link. That is concrete enough for an agent to know this is the 'getting started / sign-up process' explainer. It does not explicitly contrast itself with siblings like policies or get_plan, so it stops short of 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?

'Use when someone asks how to get started' gives a clear triggering condition, and 'there is no sign-up inside an AI assistant' pre-empts a likely misuse (trying to actually enroll). No explicit when-not / alternative-sibling routing is offered, so it is not a 5.

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