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

Annotations already indicate readOnlyHint=true and destructiveHint=false. The description adds useful behavioral context: it returns aggregated county-level statistics and treats a missing county as 'all counties.' It does not detail response shape, but that is not critical for a read-only stats tool with no output schema.

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?

Two sentences with no filler. The core behavior is front-loaded, and the alternative tool guidance is placed in the second sentence without unnecessary explanation.

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 simple two-parameter, read-only statistics tool with full schema coverage and a clear sibling reference, the description is complete. An agent has enough context to select the tool, know when to use it, and understand the effect of omitting county.

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 the schema already documents both year and county parameters. The description reinforces the 'omit county for all counties' behavior but does not add meaningful parameter detail beyond what the schema provides. 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 states a specific resource ('county figures') and the data categories it returns (medians, employment, aid), and explicitly distinguishes itself from sector_stats by geography vs. EMTAK. An agent can immediately tell what this tool does and how it differs from its closest sibling.

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 explicit routing guidance: use sector_stats when the question concerns an EMTAK rather than a place. It also clarifies the default behavior when county is omitted, which is essential for correct invocation.

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