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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, non-destructive). The description adds the FRED_API_KEY requirement and the exact fields returned, which are meaningful beyond annotations. It does not discuss rate limits or error behavior, but this is a low-risk read-only search tool.

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?

The description is front-loaded with a crisp purpose statement and uses clear bullet sections for usage, common IDs, and prerequisites. It is slightly longer than strictly necessary—the source line adds little—but it remains scannable and well organized.

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 read-only search tool with an output schema and strong annotations, the description covers purpose, return fields, prerequisites, and the correct follow-up tool. Minor omissions such as error handling or explicit pagination behavior are low risk and partly covered by the schema.

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 description clarifies that search is by keyword and suggests useful search topics (interest rates, inflation, GDP, unemployment, money supply). However, it does not explain limit, order_by, or the params wrapper; the nested schema documents those details, so the description adds only moderate value beyond the schema.

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 description opens with a specific verb and resource: search the FRED database by keyword, and it enumerates return fields (series ID, title, frequency, units, seasonal adjustment, date range). It also distinguishes itself from the sibling GetFredSeriesData by framing this as the discovery step before fetching data.

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 'Use this tool when' list gives concrete decision criteria: finding the right series ID, discovering available macro data, and obtaining context for financial analysis. It explicitly names GetFredSeriesData as the next step and even lists common series IDs to make the search-to-fetch workflow unambiguous.

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