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

The description claims the tool works for 'any of 3,222 US counties' but the input schema has no parameter to specify a county. This is a significant behavioral inconsistency that leaves the agent unable to select the target county, and the description does not clarify how the county is determined.

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 concise and front-loaded, with the main purpose in the first sentence, usage guidance in the second, and an update cadence note in the third. Every sentence provides useful information without fluff.

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?

The tool is described as returning per-county scores, yet the schema only includes an optional 'days' parameter with no county selector. No output schema exists, and the description fails to explain how to obtain a score for a specific county, making the tool practically incomplete.

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 schema fully documents the optional 'days' parameter, but the description never mentions it and instead implies a non-existent county selector. This adds confusion rather than meaning to the actual parameter.

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 clearly states the tool returns a 0-100 public library access score for US counties, naming specific measures and output fields. This is a specific verb and resource that distinguishes it from sibling tools.

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 provides explicit use cases such as library access, civic/educational infrastructure, digital-equity gaps, and grant timing, giving clear context for when to call. However, it does not mention exclusions or name alternative tools.

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