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

Annotations already declare the tool read-only, idempotent, and non-destructive, so the description does not need to repeat that. It adds meaningful behavioral details beyond annotations: the scale of coverage ('800,000+'), result ordering ('ranked by popularity'), and output shape ('series IDs and titles'). No contradictions with annotations are present.

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 two sentences with no filler: the first states purpose, scope, and output; the second gives a crisp usage rule. Everything included earns its place, and the most decision-relevant information is 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 search tool with one required parameter and rich annotations, the description supplies enough context to select and invoke it correctly. It names the output format (IDs and titles), explains ranking, and gives the use case. The absence of an output schema is partly mitigated by the description's mention of the return contents, though it does not detail limit/pagination behavior beyond 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?

Schema coverage is 100%, so each parameter is already documented in the input schema, including the search_type enum and examples for search_text. The description does not add parameter-level meaning beyond what the schema provides, which matches the baseline for high schema coverage.

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 states a specific action ('Full-text search'), a specific resource ('FRED's 800,000+ economic series'), and the concrete output ('matching series IDs and titles ranked by popularity'). It clearly distinguishes this tool from siblings like fred_series_info or fred_observations by framing it as the discovery/search entry point rather than a lookup or data-retrieval tool.

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 gives an explicit condition for use: 'Use when you don't know the exact series ID.' This implies the sensible alternative (use a direct series lookup when the ID is known), though it does not name a specific sibling tool or state explicit exclusions. The guidance is clear enough for an agent to decide when to invoke fred_search.

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