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

With no annotations, the description carries the full behavioral burden and does unusual work: it discloses revision handling ('revisions never pose as print-day numbers'), the surprise-vs-expectation methodology (market-implied when a prediction market exists, else trend-model), the monthly cadence, and the $0.02 x402 price. It stops short of auth/rate-limit/error behavior, keeping it below a 5.

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 opening fragment 'Housing starts (Census, monthly): latest print, revisions, surprise' front-loads the essence, and subsequent sentences each add a distinct fact (revision semantics, expectation source, release date, series length) rather than padding. The trailing HTTP/price/docs bracket is compact metadata.

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 no output schema, no annotations, and no parameters, the description must supply the return contract itself, and it does: it names the source, cadence, fields returned, revision flag semantics, surprise expectation source, next release date, and the 12-observation series length, plus a docs URL. Nothing an agent needs to interpret the response is missing.

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 input parameters, so per the rubric the baseline is 4. There is nothing for the description to clarify beyond confirming the series is already bound, which it does via the FRED/ALFRED reference.

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 delivers the latest Housing starts print from Census via FRED/ALFRED – and enumerates the exact payload (first-release vs latest value, revised flag, surprise, next release date, 12-obs mini-series). It distinguishes itself from the generic sibling by noting it is 'the same shape as /v1/econ/:series bound to housing-starts,' so an agent can tell it apart from econ_series and from econ_series_building-permits without opening a 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?

Usage is only implied: naming the Census/FRED source and the 'monthly' cadence plus the sibling relationship tells the agent roughly the domain, but there is no explicit when-to-use vs when-to-use-an-alternative guidance (e.g. this vs econ_series or econ_calendar). No exclusions or prerequisites are stated.

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