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

Annotations already declare readOnlyHint=true and idempotentHint=true. The description adds 'Read-only public research data. No account access, no order placement or fund transfers. Not investment advice,' which reinforces safety and purpose beyond what annotations provide. It doesn't contradict annotations, and the added context is useful for the agent's risk assessment.

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?

The description is compact, front-loading the core function (boards) and then addressing critical usage and safety points in a few short sentences. Every sentence adds value, with no extraneous content.

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?

Given the tool's complexity (6 parameters, output schema present) and rich annotations, the description covers the essential aspects: board enumeration, time_range constraint, alternative tool routing, and safety disclaimers. The output schema handles return-value details, so nothing critical is missing for correct usage.

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 covers 100% of parameters with detailed descriptions (e.g., limit, time_range, ranking_type). The description adds minimal new parameter information beyond re-stating the time_range constraint for gainers/losers, which is already in the schema. Thus it meets the baseline for full schema coverage without significantly enhancing semantics.

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 clearly states the tool retrieves coin rankings across named boards (popular, gainers/losers, etc.) and explicitly distinguishes it from get_coin_info and search_coins, which are sibling tools. The verb 'get' is implied by the title and the description's focus on board selection makes the purpose unambiguous.

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?

Explicitly tells the agent when to use alternatives: 'Single match→get_coin_info. Filtered list→search_coins.' It also specifies that time_range only applies to gainers/losers, providing clear usage constraints without ambiguity.

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