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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuine context beyond that: the rolling 12-month aggregation window and the domain meaning of fails-to-deliver. It stops short of stating sort direction, coverage universe, or result payload, so it adds value but not richly.

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 the concrete ranking definition before the interpretive gloss. The second sentence earns its place by telling an agent why this metric matters, though it edges toward background narrative rather than invocation guidance.

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 read-only ranking tool with annotations covering safety, the definition is workable. With no output schema, though, it should indicate what each ranked entry contains (symbol, total FTD shares, window) and confirm the ranking order — details an agent needs to interpret results that are currently left unstated. The parameter count is trivial (1) and fully covered.

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 the single 'limit' parameter is fully documented in the schema (default 100, max 500). The description adds no syntax, unit, or default information, so the baseline of 3 is correct when the schema does the heavy lifting.

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 ('securities ranked by total fail-to-deliver shares') plus the scoping window ('rolling 12-month'). An agent can tell this is a ranked leaderboard rather than raw lookup. However, it never names the obvious sibling fails_to_deliver_search to sharpen the distinction, so 4 rather than 5.

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 is implied by the word 'leaderboard' — this is the top-N ranked view vs. a per-symbol search. But there is no explicit when-to-use, no when-not, and no named alternative such as fails_to_deliver_search or short_interest_search. An agent must infer the routing decision.

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