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

With no annotations, the description carries the full behavioral burden. It does add one genuinely useful operational fact — the '1 credit' cost — but says nothing about authentication, data freshness, what the leaderboard contains, or what a call returns.

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 short fragments, front-loaded with the resource name and the cost signal, with no wasted text. It is efficient, though its brevity edges toward under-specification rather than ideal density.

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 tool with no annotations and no output schema, the description is too thin: the return value (columns, sort order, ranking basis), the month format, and the update cadence are all left unexplained. An agent can guess but cannot call this confidently.

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 is one parameter (month) with 0% schema description coverage; the pattern ^\d{6}$ implies a YYYYMM format but is undocumented. The description never mentions the month parameter at all, so it does not compensate for the coverage gap.

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, the 'Stripe official referral monthly leaderboard', which is distinguishable from every sibling (timeline, usage, pulse, words, score, radar, trends). However it is a noun phrase with no verb and the parenthetical 'signal of new players who have completed the closed loop' is dense jargon that doesn't sharpen what the tool actually returns.

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?

The parenthetical hints at what the data represents (closed-loop players), but there is no explicit guidance on when to call this versus the many other analytics siblings, no prerequisites, and no exclusions. The agent must guess at the use case.

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