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

With no annotations, the description carries the burden of behavioral disclosure. 'List' indicates a read-only operation, but no details are provided about response format, pagination, permissions, or side effects. It adds minimal context beyond the obvious non-destructive nature.

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 concise sentences front-load the core purpose and mention the filter. Every word earns its place; no fluff or redundancy.

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 list tool with one optional parameter and no output schema, the description is sufficient: it states what is listed and that filtering is possible. It does not elaborate on possible chainTypes values beyond the schema example, but the tool's simplicity does not demand more.

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 100% (chainTypes is described as comma-separated chain types with an example). The description adds no new meaning; it repeats the schema's example (EVM,SVM). Baseline 3 applies because the schema fully explains 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 clearly states the action ('List') and the resource ('supported chains'), making the tool's purpose unambiguous. It is distinct from sibling tools that operate on other resource types like tokens or quotes. The optional filter is mentioned as a secondary feature.

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 (call to list chains, optionally filter by chainTypes) but does not explicitly state when to choose this tool over alternatives or provide exclusions. No sibling differentiation is stated, though the resource name inherently separates it.

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