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

The description discloses that the tool performs a lookup and lists output categories, which implies a read-only operation. However, with no annotations provided, it does not cover edge cases like unsupported symbols, case sensitivity, or any external dependencies, leaving some behavioral aspects undisclosed.

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 composed of two concise sentences. The first sentence states the action and scope, while the second lists the return fields. Every word earns its place, and the description is front-loaded with the primary purpose.

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 single-parameter lookup tool, this description is adequately complete: it defines the input domain and the expected output categories. It does not discuss error handling or limitations, but given the tool's simplicity and full schema coverage, these are not critical omissions.

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 schema description already covers 100% of the single parameter 'symbol' with explicit examples (USDC, USDT, EURC, etc.). The tool description itself does not add additional meaning beyond what the schema provides, so the baseline of 3 applies.

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 verb 'Look up' and the resource 'Digital Token Identifier (ISO 24165/DTI)' for stablecoins and crypto assets. It also enumerates specific return fields (DTI code, ISIN mapping, networks, MiCA status, ISO 20022 reference), which distinguishes it from sibling tools like mica_cross_check or stablecoin_iso_profile.

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 through the purpose: use when you need DTI codes or related information for a stablecoin. No explicit guidance is given on when to prefer this tool over siblings such as stablecoin_iso_profile or mica_cross_check, and no exclusions are mentioned.

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