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

Annotations already declare readOnlyHint=true, and the description aligns with that by describing a listing/read operation. The description adds useful behavioral context by enumerating the returned data fields and explaining the interpretive role of utilization, going beyond the structured annotations.

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, no filler, with the core scope stated first and a meaningful explanatory clause second. Every sentence earns its place.

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 simple read-only listing tool with one well-documented optional parameter, the description plus annotations and schema fully cover what an agent needs: what the tool returns, why it matters, and that it is safe to call.

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% for the single optional index parameter, including an enum and guidance to omit it for Stacks indices. The description adds no new parameter-level detail, which is acceptable because the schema already fully documents the parameter.

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 uses a specific verb ('List') and a clear resource ('every venue and asset in an index'), with concrete output fields (borrow rate, supply rate, utilization, depth, weight). This distinguishes it from sibling tools like get_rate or compare_rate, which focus on rates or comparisons rather than the underlying market composition.

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 implies usage for understanding why an index rate sits where it does, especially via utilization. However, it does not explicitly state when to use this tool versus alternatives such as get_rate or compare_chains, nor does it mention exclusions or prerequisites.

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