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

Annotations already declare readOnly/openWorld/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely new behavioral context: the ranking basis (profit or volume) and that results include usernames plus wallet addresses intended for chaining into pm_portfolio. It stops short of noting data freshness or pagination limits beyond the schema's 25-row cap.

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?

Front-loaded with the trigger condition and two sentences total, both earning their place. The long inline enumeration of categories is slightly padded and duplicates the schema enum, but it stays readable.

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?

With no output schema, the description compensates by stating what comes back (ranked leaderboard, usernames, wallet addresses) and how to use it. For a read-only ranking tool with all four params documented, nothing material 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?

Schema description coverage is 100% and three of four params are enums with documented defaults, so the schema already carries the semantics. The description enumerates the period and category values but adds no format or interaction detail beyond the schema; baseline 3 applies.

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 ('Returns Polymarket's own leaderboard ranked by profit or by volume') and pins the domain to Polymarket traders, which separates it cleanly from pm_market, pm_search, and the other siblings.

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 explicit trigger phrasing ('who the best or biggest... traders are, who made the most money today, this week, this month or all time, or who leads in a category') and names the downstream alternative by stating wallet addresses are 'to pass to pm_portfolio'.

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