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

Beyond readOnlyHint, openWorldHint, idempotentHint, the description reveals that FRED is permanently disabled and will return an explanatory disabled response, that dbnomics supports dated editions for reproducibility, and that every response includes a full citation. These are valuable behavioral details not present in annotations.

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 information-dense but well-structured: main action first, followed by id format breakdown, disabled source exception, capabilities, and alternative. Each sentence adds unique information, earning its place.

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?

Despite no output schema, the description covers the tool's scope, exceptions, capabilities, and alternatives. It mentions citation in responses, providing some output context. For a complex tool with multiple id formats, it is quite complete.

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 substantially expands on series_id, detailing all supported id formats with examples and requirements. It also mentions year filters and transforms (yoy, pct_change, index), covering start_year, end_year, and transform parameters. This compensates for the limited schema descriptions on those params.

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 explicitly states it fetches any supported series by explicit id, enumerates the id formats, and distinguishes from get_indicator by advising preference for common indicators. It clearly specifies the resource (series) and the action (fetch).

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?

It explicitly says to prefer get_indicator for common indicators, and notes that FRED ids are permanently disabled, making them unretrievable. It also gives contextual requirements like 'needs country' for worldbank and imf ids, guiding appropriate usage.

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