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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds useful context beyond these: it is free, requires no payment, no wallet, and no arguments, which is exactly what an agent needs to know before invoking a preview tool.

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?

One tightly written sentence front-loads [FREE] and the core purpose, then adds the practical benefit. Every clause earns its place.

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 zero-argument preview tool with no output schema, the description supplies the key missing context: it is free, self-contained, and requires no inputs. The title supplies the sample content details (activity, balances, OFAC check, risk summary), so nothing critical is left unexplained.

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 zero parameters, so the baseline is 4 per the rubric. The description confirms 'no arguments needed,' which aligns with the empty schema but does not add further parameter meaning.

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 states exactly what the tool returns ('A sample response for wallet_profile') and explicitly distinguishes it from the paid sibling by calling it a free preview. An agent can tell it apart from wallet_profile without opening either schema.

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 clearly indicates when to use it: to see the shape before paying 0.03 USDC for wallet_profile. It does not explicitly state 'use wallet_profile for real data' or list exclusions, but the alternative is strongly implied.

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