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

With no annotations, the description carries the transparency burden. It discloses output structure (score range, band categories, deduction inputs, citation), and adds critical limitations ('never predictions, never financial advice'). It lacks error-handling or look-up behavior details, but for a simple read tool it provides substantial behavioral context.

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?

Two sentences with zero redundancy: the first front-loads the tool's output and scope; the second is a crucial disclaimer. Every sentence earns its place, and the structure is immediately scannable.

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, so the description must explain return values; it does so with concrete details (score range, bands, deductions, citation). For a one-parameter tool, this is sufficient for correct invocation, though it omits failure scenarios or how deductions are structured. Minor gap, but not enough to lower to a 3.

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?

Schema coverage is 100% and the description adds no extra parameter-level meaning. The description does not clarify how the 'coin' parameter is matched beyond the schema's existing explanation of id/symbol/name resolution. Baseline 3 is appropriate 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 states a specific verb+resource ('survival rating alone for one coin') and enumerates exactly what is returned: score, band, deductions, and citation. It differentiates itself from the 'full profile' sibling by emphasizing it is the standalone rating and faster, making its purpose unmistakable.

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 clearly implies when to use this tool ('Faster than the full profile') – i.e., when only the survival rating is needed, not the full coin profile. However, it does not explicitly name the alternative (e.g., get_coin_profile) or state when not to use it, leaving some inference to the agent.

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