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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered. The description adds genuine behavioral context beyond them: 'Updated daily' freshness, the caveat that feed-driven venues report the lowest of recent readings, and that each table names its own time window. Rate limits and pagination behavior are not mentioned.

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?

Content is front-loaded ('Today's rates on one venue') and the enumeration of table types is compact. It is a single dense paragraph with little waste, though the trailing caveats about feed-driven venues and daily updates could be tightened.

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 correctly carries the burden of describing the return shape (four table families with named metrics) and notes freshness. Minor gaps remain: nothing about ordering, empty-result behavior, or how limit applies across multiple tables.

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% (venue enum, asset substring filter, limit default/max), so the schema carries parameter meaning. The description explains what the returned tables contain but adds no syntax or filtering semantics 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 gives a specific verb+resource ('Today's rates on one venue') and then enumerates exactly what is returned: lending supply APY, borrowing costs, isolated borrow markets, and liquidity pools with fee APR/TVL/24h volume. This clearly separates it from get_market_prices and analyze_wallet in substance, though it never explicitly names a sibling to route against.

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?

There is no when-to-use or when-not-to-use guidance and no mention of alternatives such as get_market_prices. The agent can infer that this is the per-venue rate lookup, but nothing in the text states the condition that should select this tool over its siblings.

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