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

With no annotations, the description carries the burden of behavioral disclosure. It does state the output behavior (returns PASS/WARN/BLOCK verdict with reasoning), which implies a read-only analysis. However, it does not mention whether external lookups occur, how unknown symbols are handled, or any limitations, so it is minimally acceptable but not rich.

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 concise sentence that front-loads the purpose and clearly states the output format. Every word adds value, with no redundant information.

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 tool with one parameter, no output schema, and no annotations, the description is fairly complete: it explains the purpose, the regulatory context, and the output type. It could be enhanced by specifying the structure of the reasoning or any prerequisites, but the core context is sufficient for a simple check tool.

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 input schema has 100% coverage for the single 'symbol' parameter, describing it as 'Stablecoin symbol to check'. The description does not add extra meaning beyond the schema, such as accepted formats or examples. Baseline 3 applies since the schema fully documents 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 tool's function: checking whether a stablecoin can be legally used in EU ISO 20022 payment flows after MiCA enforcement. It uses a specific verb ('Cross-check') and resource ('stablecoin legality'), and the return format (PASS/WARN/BLOCK with reasoning) distinguishes it from sibling tools like 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?

The context for use is implied: it is for assessing legal usability of a stablecoin in EU ISO 20022 payments after MiCA. However, there is no explicit guidance on when to use this tool versus alternatives like stablecoin_iso_profile or sanctions_screen_iso, nor any exclusion criteria.

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