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

With no annotations, the description carries the full behavioral burden and does so thoroughly: it discloses payment requirements, the 402 flow, that the server holds no wallet, dataset limitations, unknown-field behavior, and charge/no-charge conditions.

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 front-loaded and mostly purposeful, covering payment and dataset constraints that matter for invocation. It does repeat the pricing in two places and is somewhat verbose, but the structure remains usable.

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 paid API, lack of output schema, and lack of annotations, the description provides the needed context: dataset coverage, returned fields, citation/license behavior, unknown values, error handling, and payment retry mechanics.

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%, so the input schema already documents chain, symbol, and address. The description adds dataset scope but does not provide significant additional parameter semantics beyond the schema.

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 identifies the resource and returned fields: stablecoin token facts including symbol, name, decimals, contract address, chain, and issuer. It is easy to distinguish from chain-level tools, but it does not explicitly name sibling alternatives or contrast itself with them.

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?

Usage is implied for looking up stablecoin metadata, and the description states dataset coverage and that missing tokens return 400/404 without charge. However, it does not explicitly say when to use this versus siblings such as get_chain or stablecoin_rails.

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