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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is covered without the description. The description adds no behavioral context at all — no mention of units, lag, pagination, or what the annual-change figure represents.

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?

It is short, but the URL path is duplicated verbatim, which is pure waste. The one useful clause (describe_operation for schemas) is buried after the redundancy rather than front-loaded.

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 tool with an opaque free-form query parameter and no output schema, the description should explain what the endpoint returns and how to shape the query. It does neither, leaving the definition inadequate for correct invocation despite the annotations covering safety.

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?

Both parameters (query and params) have 0% schema description coverage, and the description does not mention either. With a free-form 'query' object and an empty 'params' object, the description leaves the agent with no idea what can or should be passed.

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 text is essentially a restatement of the tool name and title: it repeats the same URL path twice and adds only an operation ID. An agent can infer the resource (CPI annual change) from the path, but there is no verb-level explanation of what the call returns or does, and nothing that separates it from the many sibling CPI tools.

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?

There is no statement of when to use this versus cpi_current, cpi_history, cpi_series, or cpi_calculate. The only actionable pointer is 'describe_operation provides native request schemas', which is a schema-discovery hint rather than usage guidance.

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