datafeed_info

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

No annotations exist, so the description carries the full burden, and it fails to describe the tool's own behavior - it describes a product's plans, prices, and a separate HTTPS subscribe endpoint instead. The text is also truncated mid-sentence ("returns an API key plus "), so even the one behavioral claim it starts to make is cut off, leaving the agent with no idea what a call returns or costs.

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?

Roughly half the text is pricing and subscription mechanics (three tiers, call limits, USDC-on-Base payment) that do not help an agent decide to call a zero-argument info tool. It is also visibly truncated, ending mid-sentence, which is a structural defect rather than conciseness.

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?

For a simple zero-parameter info tool with no output schema, the description needs to say what calling it returns, and it does not. Instead it points the agent at an external POST subscribe endpoint while omitting the tool's own response shape, so an agent cannot confidently invoke it or set expectations.

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 carries no semantics that the description needs to supplement. Baseline 4 applies; the pricing-tier enumeration is irrelevant to parameters and does not add or detract from parameter meaning.

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 name and first line establish the resource (AgentWorld economy data feed) and enumerate its contents (treasury USDC, AGWC price, agent population, Gini, city GDP, job market depth), which is informative. However, the description never states what invoking the tool actually does - it reads as product marketing and pivots to "Subscribe: POST https://..." which suggests a purchase action rather than an informational lookup. It also does not differentiate itself from siblings like get_economy, data_economy, or data_catalog.

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?

No when-to-use guidance is given relative to the many sibling data tools. The "[FREE]" prefix implies this call is free versus the paid subscription it advertises, but that inference is left entirely to the reader. There is no statement of preconditions, exclusions, or which alternative to pick for live economy data without subscribing.

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