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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds valuable context beyond those: 'no auth required', '95%+ population coverage' (clarifying potential data gaps), and the public-domain US Gov source. It also specifies the return content (raw counts, rates, clearance counts), complementing the read-only profile without contradiction.

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 four sentences and front-loaded with the primary action and resource. It packs useful facts (granularity, return metrics, coverage, source, auth) without fluff. The offense-type enumeration is partially redundant with the schema but serves as a quick reference, earning 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?

Given the annotations covering safety and an output schema handling return values, the description supplies all essential calling context: monthly granularity, date-range behavior implied, offense-type selection, data coverage caveat, source provenance, and authentication requirement. Nothing an agent needs to invoke this tool correctly 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%: from_month documents the available start date (01-1979), to_month documents the default, and offense_type explains composite categories. The description's offense-type list and month format details are redundant with the schema, adding no significant new meaning beyond what the structured fields already provide.

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 opens with a specific verb and resource: 'Retrieve monthly national Uniform Crime Reporting (UCR) crime statistics from the FBI Crime Data Explorer.' It distinguishes itself from sibling tools by explicitly stating 'monthly' and 'national', which separates it from fbi.crime.national_annual and fbi.crime.state_annual, and 'national' separates it from fbi.crime.state_offenses.

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 implies its usage for monthly national crime data by stating the granularity and coverage, but it does not explicitly state when to use this tool over alternatives or mention the sibling annual/state tools. There are no exclusions or when-not-to-use guidance, only the data coverage note about participating agencies.

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