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

Goes well past the annotations: discloses that reads come from a committed snapshot (so latency is low), that the snapshot date is included in the answer, and that failed calls are free while repeats are charged. This is consistent with idempotentHint=false and readOnlyHint=true rather than contradicting them.

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-loads what the tool returns and the country identifier before moving to sourcing and billing. Dense but almost every clause carries information; the pricing detail is slightly over-weighted relative to the core semantics.

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, yet the description explains the shape of the return (1-10 annual values, newest first, snapshot date included). Combined with the source, licensing, and cost model, an agent has everything needed to call it correctly and interpret the result.

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 with ranges and formats. The description repeats the country format (ISO code or English name) and adds the newest-year-first ordering, but that ordering concerns output, not parameter meaning. Baseline 3 applies.

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 the exact metric (annual % change in CPI), source (World Bank), and the distinguishing sibling set (econ_gdp, econ_unemployment, econ_population) is implicitly excluded by naming CPI specifically. An agent knows precisely what this returns without opening the 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?

Gives concrete use cases ('real-return, pricing and macro questions') and a worked example (country=SE), which is more than most tools offer. It does not explicitly say when to pick econ_gdp or econ_unemployment instead, so routing between the econ_* siblings is still inferred rather than stated.

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