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

No annotations are provided, so the description carries the full burden. The verb 'List' implies a read-only operation, which is a behavioral hint, but the description does not explicitly state safety, data source, pagination, or scope limitations. It is minimal but not misleading.

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 a single, front-loaded sentence that conveys all essential information without any filler. Every word earns its place, and it is immediately clear what the tool does.

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 no-parameter list tool, the description sufficiently explains the purpose and return nature (a ranked list). However, it does not clarify whether 'major' implies a cutoff or specific ranking details, and with no output schema, a tiny bit more context could improve completeness. Still, it is adequate.

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?

The tool has zero parameters, so the baseline is 4. The description does not need to add parameter-level details, and the empty schema already captures the fact that no arguments are required.

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') combined with a clear resource ('major DeFi protocols on Arbitrum') and a qualifier ('ranked by TVL'). This precisely distinguishes it from sibling tools like arb_protocol_health or arb_defi_yields, which focus on health or yield data.

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 usage context is implied: if you need a ranking of protocols by TVL, this tool is appropriate. However, there is no explicit statement of when to use it versus alternatives, nor any mention of when not to use it or exclusions. Sibling tools exist but are not referenced.

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