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

With no annotations, the description carries the burden of disclosing behavior. The verb 'List' clearly indicates a read-only operation with no side effects, and specifying 'all known' and the included attributes gives a good sense of the output. It does not mention edge cases like pagination or filtering, but this is minor given the zero-parameter interface.

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, self-contained sentence with no redundancy. It front-loads the action and clearly states the output scope and content.

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 simplicity of the tool (no parameters, no output schema, no annotations), the description is adequately complete. It tells the agent what entities are returned and what details are included. It could benefit from mentioning the return format explicitly, but the basic usage is clear.

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?

There are no parameters, so per the rubric the baseline is 4. The description does not need to explain parameter semantics beyond noting the output fields, which it does.

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 a specific verb ('List') and resource ('token issuers'), and further specifies the attributes included (MiCA authorization status and tokens). This distinguishes it from sibling tools like issuer_profile (which implies a single entity) and entity_list (which may cover a broader entity set).

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 implies its usage: when an agent needs an overview of token issuers and their compliance status. However, it does not explicitly mention when not to use it or provide alternatives, such as preferring issuer_profile for detailed information on a single issuer.

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