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

Annotations only cover read-only and closed-world safety, so the description carries useful extra weight: it discloses the 2005-onward coverage window, the 21-indicator scope, CC BY 4.0 licensing, and a concrete price of $0.02 USDC on Base via x402. That cost/auth context is exactly the kind of thing annotations cannot convey. It stops short of describing error behavior or result shape beyond the value/year framing.

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?

Two dense sentences with the core purpose front-loaded; the long indicator enumeration is bulky but each item is load-bearing for the agent's decision. Pricing and licensing are appended compactly at the end with no filler.

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, the description does the work of explaining returns ('latest value and year plus annual history'), which is sufficient for an agent to anticipate the response shape. Coverage window, indicator list, country input formats, and cost are all present; only failure modes and pagination/size limits are absent.

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?

Schema description coverage is 100%, so both parameters are already documented and baseline is 3. The description adds only indirect context for 'years' by stating history begins in 2005, which helps bound the valid range but does not explain the parameter itself.

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: a country economic profile drawing 21 named World Bank WDI series, each with a latest value and annual history from 2005. The enumerated indicator list makes the scope unmistakable, though it never explicitly contrasts itself with siblings like macro_indicator or macro_rank, so differentiation is inferred rather than stated.

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 implies usage (fetch a broad multi-indicator profile for one country) but never says when to prefer this over macro_indicator (single series) or macro_rank (cross-country ranking). An agent must infer the boundary from names alone.

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