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

Annotations already cover the safety profile (readOnlyHint=true), but the description adds genuine behavioral context beyond them: the live/test mode concept and the non-obvious constraint that a token only sees tickets and registrations of its own mode. That scope limitation is the kind of thing that changes how an agent interprets every subsequent call. It stops short of 5 only because it doesn't describe error/auth-failure behavior.

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 compact sentences, front-loaded with the core action and the highest-value instruction ("call this first"). The parenthetical about token mode earns its place by explaining a real scoping constraint rather than padding.

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?

There is no output schema, so the description carries the return-value burden — and it does: it names what comes back (account slugs, lookup mode). For a zero-param, read-only discovery tool with annotations covering safety, nothing needed to call it correctly is missing.

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 per the rubric the baseline is 4. Nothing in the description is needed to explain inputs, and it correctly documents that the tool is parameterless by implication.

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?

States a specific verb and resource combo — confirm the token, enumerate reachable account slugs, and report the lookup mode — which no sibling tool does. It also maps to the underlying endpoint (GET /hello), so an agent can distinguish it from all the list_* and get_* siblings at a glance.

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?

Explicitly says "Call this first to discover account_slug", giving a concrete prerequisite/ordering rule rather than an implied one. Since this is a discovery tool with no real alternative, naming the ordering constraint is exactly the guidance an agent needs.

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