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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds context beyond these: it specifies the tool is a paged directory, lists the returned fields, and notes it deals with active exchanges. It doesn't describe pagination mechanics in detail, but the annotations lower the bar and the description still adds meaningful behavioral context.

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 three sentences with zero fluff. It front-loads the core purpose and data fields, then provides usage guidance, then alternatives. Every sentence earns its place, and the structure is clear and efficient.

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 simplicity (two optional pagination params) and the presence of an output schema that likely documents the response structure, the description covers all essential aspects: what it returns, how to page, when to use it, and alternatives. It doesn't need to explain return values because the output schema handles that. The description is complete for an agent to decide when and how to call it.

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 0%, so the description must compensate. It mentions 'Page with `per_page` and `page`' which clarifies the purpose of both parameters as pagination controls, but it doesn't provide additional details like acceptable ranges or how they interact. The schema provides defaults and a maximum for per_page, so the description adds minimal semantic value beyond naming the params. A score of 3 is appropriate given the partial compensation.

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 returns a paged directory of active exchanges and enumerates the specific fields included. It distinguishes itself from sibling tools by naming get_coingecko_exchanges_list and get_coingecko_exchanges_id as alternatives, making its 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?

The description provides explicit guidance on when to use this tool ('Use it to rank or filter venues by trust and volume') and when not to, with specific alternatives and conditions: 'If you only need the identifier mapping, get_coingecko_exchanges_list returns all of them with no market data and no paging; for one venue in full use get_coingecko_exchanges_id.' This leaves no ambiguity.

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