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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so the safe-read profile is covered. The description adds genuinely useful context beyond that: the normalization baseline (96 base-city average = 1.00), support for current and yearly series, and that medians carry computed:true. It does not describe pagination behavior, but that is a minor gap.

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 purpose is front-loaded and the content is well-organized with concrete examples. The main cost is the full bilingual duplication, which doubles length without adding information, but the underlying prose is efficient.

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?

With an output schema present and safe-read annotations, the description needn't explain return values or permissions. It covers the reference baseline, historical vs current data, and geo formats, which is enough for an agent to call the tool correctly; only pagination guidance (limit/offset interaction) is left entirely to the schema.

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 all five parameters. The description's geo format examples (zip:28533, Cherry Point, NC, country:JP) and its note that medians are computed:true largely restate schema content, so it does not add meaning beyond the structured fields. Baseline 3 applies.

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+resource: it retrieves DoD Area Cost Factors by installation (96 base-city average = 1.00) and USACE CWCCIS state adjustment factors. It also draws a boundary against the sibling verify_fair_price by clarifying it is 'not a test of whether a quote is fair,' letting an agent distinguish it without opening either schema.

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 clear context for use ('budgeting factors') and an explicit exclusion ('not a test of whether a quote is fair'), which implicitly routes fairness checks elsewhere. It stops short of naming the alternative tool explicitly, so it is strong but not fully prescriptive.

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