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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive behavior. The description adds valuable context beyond annotations: source (FBI UCR / CDE), public domain, no auth required, data available from 1979, aggregation from monthly reporting, and returned metrics. No contradiction with annotations.

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?

Four sentences with no filler. The main retrieval purpose and output metrics are front-loaded, examples clarify use cases, and the source/auth note is compact. Every sentence 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 read-only, single-required-parameter tool with a full output schema and all parameters described, the description covers what the tool does, what it returns, available date range, intended use cases, source, and auth requirements. Nothing essential is missing.

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 100%, so each parameter is already documented in the schema. The description adds contextual framing (multi-decade ranges, annual totals, rate per 100,000) but does not introduce meaning beyond the schema for the parameters themselves. Baseline of 3 is appropriate.

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?

States a specific verb and resource: 'Retrieve national year-over-year annual crime totals from FBI UCR data'. It distinguishes from state-level siblings by explicitly being national and annual, and lists return metrics. The title reinforces the resource without vagueness.

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?

Provides clear context with 'Ideal for long-term trend analysis' and concrete example questions. It does not explicitly name alternatives such as fbi.crime.state_annual or fbi.crime.national_offenses, but the national/annual framing and examples make the intended use clear.

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