usas_spending_over_time

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

Annotations already declare readOnlyHint and openWorldHint. The description adds behavioral context beyond annotations by specifying that grantObligations/idvObligations are returned as null (not 0) to avoid misleading implications. This is a meaningful behavioral trait. It also mentions that the exclusion of non-contract types is disclosed in _meta.

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 a single, well-structured paragraph that front-loads the core purpose, then adds exclusions, behavior, and a usage example. It is relatively concise at ~100 words. Minor parenthetical aside about _meta adds a bit of density but is relevant.

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 description covers the tool's output (time-series rollups), key parameters, null behavior, and gives a usage pattern. Given there is no output schema, this is fairly complete. It could mention whether grouping is required or optional, or note any pagination or result limits, but the core functionality is well-described.

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 description provides a usage example that demonstrates how to use agency ('VA') and NAICS ('541512') parameters, adding context beyond the schema. However, with 0% schema description coverage, the description does not fully explain each parameter's format or constraints (e.g., agency is a string but no example of valid codes, NAICS as a string but no length). It lists the group enum options but doesn't elaborate on them.

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 purpose as 'Time-series aggregation of federal CONTRACT spending' and explicitly excludes non-contract award types (grants, IDVs, loans), distinguishing it from siblings like usas_search_agency_spending or grants_search. It uses a specific verb ('aggregate') and resource ('federal contract spending').

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 provides a concrete usage example ('how has VA 541512 contract spending trended over the past 5 years') and explains what it returns. It implies when not to use by excluding grants/IDVs/loans. However, it does not explicitly name alternative sibling tools for those excluded types beyond noting that it matches 'other usas_search_*_spending tools'.

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