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

With no annotations, the description carries the full burden and does disclose the three values returned and the read-only nature implied by "Check". It stops short of stating auth requirements, rate limits, or the currency/unit of the balance, which matter for interpreting the result.

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, both front-loaded: the first declares what is returned, the second converts that into an actionable decision point. No filler, no restatement of the tool name.

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-param read tool with no output schema and no annotations, the description is the sole source of return-value information, and it names the three returned quantities plus the decision it enables. It would be complete if it also said what unit the balance is denominated in and how to interpret a low or zero balance.

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 baseline there is nothing for the description to disambiguate. It correctly adds no parameter noise and spends its words on return contents and timing instead.

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?

Uses a specific verb ("Check") against three named resources: prepaid balance, this key's spend caps, and 24-hour spend. This is unambiguous against every sibling, all of which operate on quests rather than account state, so an agent can route to 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?

Gives explicit when-to-use guidance: call it before posting quests to know whether they will be paid instantly, which directly ties it to create_quest. It does not name exclusions or a true alternative tool, but no sibling overlaps in function, so the missing piece is minor.

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