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

With no annotations the description carries the full burden and does disclose meaningful behavior: revisions are flagged and 'never pose as print-day numbers', surprise is market-implied when a matching prediction market exists else trend-model, plus next release date and a 12-observation series. It also exposes pricing ($0.02 via x402) and the HTTP endpoint. It does not cover pagination or caching, but the content-level transparency is strong.

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?

Key content is front-loaded, but the opening sentence ('latest print, revisions, surprise') is immediately restated by the following sentence ('Latest Effective fed funds rate print from the Fed via FRED/ALFRED'), which is redundant bulk that could be tightened.

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 and no annotations, the description must convey the return shape, and it does list the payload components (first-release vs latest with revised flag, labeled surprise, next release date, 12-obs mini-series). Coverage is good, though it stops short of describing field formats or freshness/latency guarantees.

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, so the schema baseline is 4 and no further parameter explanation is required; the description correctly spends no effort on parameter syntax.

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 returns the Effective fed funds rate monthly series with latest print, revisions, and surprise. The phrase 'bound to fed-funds' plus the explicit metric differentiates it from the generic econ_series and from sibling series such as econ_series_cpi or econ_series_unemployment.

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 note 'Same shape as /v1/econ/:series bound to fed-funds' implicitly routes the agent to this specialization over the generic series tool, but there is no explicit when-to-use versus when-not guidance or named alternatives/enumeration of conditions.

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