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

Annotations already declare readOnlyHint=true and openWorldHint=false, but the description layers on real behavioral context: the four-year contract window, the interquartile 'middle half' framing, the dollars-obligated unit, per-figure award counts, and the five-award minimum for state-level results. That is unusually rich disclosure of how the numbers are computed and suppressed.

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?

It is front-loaded: what is shown, then the statistical framing, then the geographic scoping rule, then the vocabulary. It is one very long sentence and the 14-item job-type run-on might arguably belong in the schema enum, but each clause carries genuine information for the caller.

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?

There is no output schema, so the description carries the full burden of explaining returns, and it does: median, low/high bounds, dollars obligated, and the count behind each figure. Combined with the time window, geography threshold, and job-type list, an agent has everything needed to call and interpret this tool.

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 coverage is already 100%, so the baseline is 3, but the description goes further by enumerating the full catalog of accepted job types (Air handling unit, Backflow, Boiler, Chiller, etc.) where the schema only offers the free-text example 'chiller' or 'backflow'. It also clarifies the dollars-obligated metric and the four-year lookback that no parameter documents.

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 verb and resource: it shows what the VA has typically paid per contract for a given type of HVAC/plumbing work. It also pins down the statistic (median and middle half of awards) and the time window, which cleanly separates it from siblings like lookup_contract or location_contracts.

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 gives an implicit usage condition ('for one state when it has at least five comparable awards'), which tells the agent when a state-level answer is even possible. However, it never says when to reach for this tool instead of buying_calendar, location_contracts, or lookup_contract, so the routing guidance is implied rather than explicit.

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