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

With no annotations, the description carries the full burden and does reasonably well: it marks the call as FREE and no-input, and it specifies the response envelope. It doesn't explicitly state read-only or side-effect-free, though listing agents implies as much. The missing pieces are minor rather than serious (no pagination, no statement about whether the list is stable).

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?

Compact and front-loaded: cost/chain first, then what it returns, then the follow-up call. The lead 'FREE, X1' is terse to the point of being cryptic, but no sentence is wasted.

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?

No output schema exists, yet the description inlines the return structure, so an agent knows what it will get and how to chain into agent_tune. The only gap is what 'role' signifies and whether the station list is fixed or paginated.

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?

Zero parameters, so baseline is 4, and the description reinforces this with 'No input.' Nothing further is required.

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 names the specific resource: named agents in the X1/APEX city that have a song, and it discloses the return shape { stations: [{ name, wallet, role }] }. An agent can distinguish it from agent_tune because the description says this one gives the line-up while agent_tune gives the tune. The wording 'APEX city radio line-up' and 'FREE, X1' is somewhat jargon-heavy, but the core purpose is still clear.

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?

It gives an explicit workflow: 'Use it to pick a wallet, then call agent_tune with that wallet.' That names the sibling and states the condition for moving on. It does not state when NOT to use it, but for a zero-parameter discovery tool, little more is needed.

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