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

With no annotations, the description carries the full burden and largely meets it: it discloses that revisions are flagged separately from first-release values ('revisions never pose as print-day numbers'), how surprise is computed (market-implied when a matching prediction market exists, else trend-model), the next release date, and a 12-observation window. It also exposes the transport (HTTP GET) and the paid access path ($0.02 via x402), which is unusual and useful operational context.

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?

Front-loaded with the resource and the three headline outputs, then progressively less critical detail. The middle run-on about first-release vs latest and market-implied vs trend-model surprise is dense but each clause carries meaning; little is wasted.

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?

No output schema exists, so the description is responsible for describing the return payload and does so thoroughly (fields, revision flagging, surprise origin, horizon, release date). It also mentions the endpoint, cost, and docs link, leaving little an agent would need to call and interpret it correctly.

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 tool takes zero parameters and additionalProperties is false, so there is no parameter semantics to document. The baseline for a 0-param tool is 4.

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 resource and dataset origin: 'Building permits (Census, monthly)', then enumerates what it returns (print, revisions, surprise, next release, mini-series). The line 'Same shape as /v1/econ/:series bound to building-permits' clarifies how it relates to the generic econ_series family, though it never names a sibling tool like econ_series_housing-starts explicitly.

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?

There is no when-to-use or when-not-to-use guidance. The description does not say when to pick this over econ_series, econ_series_housing-starts, or econ_calendar, nor does it state any preconditions. Usage is only implied by the data it returns.

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