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

Annotations already provide readOnly, idempotent, openWorld, and destructive=false hints. The description adds useful beyond-annotation context: the computation is deterministic, the resource is paid at a specific x402 price, and the intended assurance domain is narrow. No contradiction with annotations exists.

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 three purposeful, front-loaded sentences with no filler. It leads with functionality, follows with usage boundaries, and closes with cost information the agent needs before invoking.

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?

The tool has no output schema and two underspecified required parameters, so the description must explain what 'descriptive benchmark statistics' means and how inputs map to outputs; it does not. It also fails to clarify how this specific benchmark feed differs from its many similarly named siblings.

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 description coverage is 0%, so the description must compensate for the undocumented parameters, but it only names them at a high level. It does not clarify how metric_fields relate to observations, whether metric_fields must exist in each observation object, or what constraints apply to values beyond the schema's min/max limits.

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 ('computes'), target resource ('caller-supplied observations ... numeric fields'), and output type ('deterministic descriptive benchmark statistics'). It clearly distinguishes the outcome-assurance family from reliability/dispute feeds, but it does not differentiate this hash-specific feed from the many sibling outcome_assurance_benchmark_data_feed variants.

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 gives an explicit intended context ('outcome assurance / trust unknown') and explicit when-not-to-use exclusions for legal, identity, sanctions, fraud, contractual, or regulatory adjudication. It does not name an alternative tool for those cases, so it stops short of the top score.

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