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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety bar is low. The description still adds real value by bounding the operation's scope (credits are managed elsewhere; no selling or purchase initiation happens here), which prevents an agent from treating it as a transactional tool.

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?

Two sentences, front-loaded with 'Read-only.' and then the payload contents. No filler, and the enumeration of player-size tiers is compact and useful 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 must convey what comes back, and it does: credits per size tier (100/500/1,000/5,000 players) plus a quiz count. Minor gap: it doesn't say whether credits are returned as a single number per tier or split by something else, but the shape is largely inferable.

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 there is nothing for the description to disambiguate; baseline is 4. The description instead spends its words on what the result contains, which is the more useful place for detail here.

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 and scope: the signed-in maker's account status, broken out as available event credits per player-size tier and a quiz count. This is clearly distinct from every sibling, which all operate on quizzes or games, so an agent can select it without opening the schema.

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?

Usage context is clear ('account status', 'credits managed on the maker's TenQueue account') and one explicit exclusion is given: it never sells or starts a purchase. It does not, however, name an alternative or contrast itself with get_capabilities, which is the sibling most likely to be confused with an account-status lookup.

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