get_coins_index

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

No annotations are provided, so the description carries the full burden. It discloses the subscription requirement ('ultra plan or higher'), which is useful context. However, it doesn't describe behavioral traits such as rate limits, pagination, response format, or whether it's a read-only operation. For a tool with zero annotation coverage, this leaves significant gaps in understanding how it behaves.

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 two sentences, front-loaded with the core purpose and followed by a critical constraint. Every sentence earns its place: the first defines the tool, and the second adds essential usage information. There is no wasted text, making it highly concise and well-structured.

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?

Given the tool has no parameters, no annotations, and no output schema, the description is moderately complete. It covers the purpose and a key constraint (subscription requirement), but lacks details on output format, behavioral traits, and differentiation from siblings. For a simple list tool, this is adequate but has clear gaps, aligning with a minimum viable score.

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 0 parameters, and schema description coverage is 100%, so there are no parameters to document. The description doesn't need to add parameter semantics, and it appropriately doesn't mention any. A baseline of 4 is applied since no parameters exist, and the description doesn't introduce confusion.

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's purpose: 'List of all coins currently available on coinranking, for indexing purposes.' It specifies the verb ('List') and resource ('all coins'), and distinguishes it from siblings like 'get_coins' by mentioning 'for indexing purposes.' However, it doesn't explicitly differentiate from 'get_exchanges_index' or other indexing tools, keeping it at 4 instead of 5.

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 provides some usage context by stating 'This endpoint requires the **ultra** plan or higher,' which implies when to use it based on subscription level. However, it lacks explicit guidance on when to choose this tool over alternatives like 'get_coins' or 'get_exchanges_index,' and doesn't mention exclusions or specific scenarios. This results in implied rather than clear guidance.

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