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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the safety profile is covered. The description adds the key non-obvious trait: it opens nothing by itself and returns guidance rather than performing the enrollment. That goes beyond what the annotations convey.

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 instruction is front-loaded, but the text crams a lot into two run-on sentences, including a dated parenthetical and an API comparison that is somewhat tangential. Informative, but not maximally tight.

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, the description covers what it does, what it does not do, and the required follow-up tool family. It does not explain what the returned steps look like or what happens if the account is not connected, but the essential call semantics are present.

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 sets the baseline at 4. The description explains the operational model (returns guidance, takes no inputs) and why the agent must follow up with browser tools, which adds useful meaning.

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 states a specific verb and resource ('Enroll users on course') and clarifies scope ('in the user's own LearnUpon account'). It implicitly distinguishes itself from siblings like learnupon_enroll_group_on_course and learnupon_add_users_to_group, but does not name those alternatives explicitly.

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 clear workflow guidance: the tool returns step-by-step instructions and opens nothing by itself, then the agent must act with cotlet_browser_* tools. It does not, however, say when to prefer learnupon_enroll_group_on_course or learnupon_add_users_to_group instead.

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