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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds behavioral context: pagination, sorting, filtering, and the conditional field addition when price_change_percentage is passed. It doesn't mention rate limits or response size, but the output schema exists and the annotations carry the safety burden.

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 dense but well-organized: it front-loads the core value proposition, then lists fields, then parameters, then use cases. Every sentence earns its place, and the sibling routing is at the end where it belongs.

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 list/market tool with an output schema and rich annotations, the description covers the main behaviors: pagination, sorting, filtering, and conditional fields. It also names the lighter alternative for simple price queries. Nothing critical is missing for an agent to select and invoke this tool correctly.

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 coverage is 64%, so the description compensates by explaining the effect of key parameters: per_page/page for pagination, order for sorting, ids/category for narrowing, and price_change_percentage for adding a field. It doesn't detail every parameter, but the schema already covers most of them. The description adds meaning beyond the schema for the most important parameters.

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 ranked market table with one row per coin and enumerates the exact fields. It distinguishes itself from siblings by naming get_coingecko_simple_price and get_coingecko_coins_id as alternatives for different use cases.

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 explicitly says when to use this tool ('leaderboards and segment scans') and when not to ('for the price of a few known coins... far lighter; for one coin in full use get_coingecko_coins_id'). This is strong routing guidance.

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