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

Annotations already declare readOnly, idempotent, and non-destructive behavior; the description adds 'deterministic', 'caller-supplied', and the $0.002 per-call price. These details provide meaningful operational context beyond the annotations. No contradiction with the annotations is present.

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?

Three compact sentences with the core behavior first, followed by domain and pricing. The negative-use sentence is somewhat list-heavy, but each sentence adds operational value and there is no filler or repetition.

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 two-parameter computational tool with no output schema, the description covers inputs, domain, exclusions, and cost, which is solid. It remains incomplete about the exact returned statistics, how metric_fields are resolved against observations, and how this feed differs from its many reliability_quality_benchmark_data_feed_* 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 carry the parameter-meaning load. It partially does: 'caller-supplied observations' maps to observations, and 'explicitly named numeric fields' maps to metric_fields. However, it does not clarify field-format expectations, missing-field behavior, or exactly which descriptive statistics will be computed.

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 action ('computes deterministic descriptive benchmark statistics') and a clear resource scope ('caller-supplied observations and explicitly named numeric fields'). It also names the intended domain ('reliability quality / vendor lock in'), though it does not explicitly differentiate among the many reliability_quality_benchmark_data_feed_* siblings.

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 positive context ('Intended for reliability quality / vendor lock in') and a clear negative list ('Do not use for legal, identity, sanctions, fraud, contractual, or regulatory adjudication'). This is stronger than merely implied usage, but it does not name a specific alternative tool or explain what distinguishes this feed from its same-family siblings.

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