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

Annotations declare readOnlyHint=true, and the description adds behavior by noting 'Updates: on source cadence' and describing normalization across all 3,222 counties. It also mentions 'History requires Gold tier' in the parameter description, adding access-level context. No 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 compact, with the purpose, use cases, and update cadence in three sentences. No redundant content.

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 index tool with no output schema, the description lists all key output fields and provides usage context and update cadence. The optional history behavior is fully documented in the parameter schema. Missing only deeper interpretation of confidence or components, which is acceptable.

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?

The single parameter 'days' has a 100% schema description covering meaning, range, and tier requirement, so the description adds little beyond the schema. Baseline 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?

The description opens with 'Returns a 0-100 per-county crime and safety score' which is a specific verb+resource with clear scope. It further distinguishes itself as the crime/safety tool by listing output fields and normalization details, making it unlikely to be confused with 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?

It explicitly states 'Call when the user asks how safe a county or area is, or about local crime levels...' providing clear trigger conditions. However, it does not name alternative tools or exclusionary cases, so it lacks when-not guidance.

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