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

Annotations already indicate readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context by explaining that date bounds accept specific formats and are 'normalised to the derived series frequency,' which is useful beyond the schema. It does not contradict 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 extremely concise: two sentences that immediately state the tool's purpose and then provide the key date-bound behavior. Every sentence serves a purpose, with no filler or redundancy.

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?

Given the presence of an output schema and rich annotations, the description is sufficient for a simple read-only retrieval tool. It covers the notable normalization behavior, but does not define what 'derived series' means or when to choose it over economic series; however, sibling context and schema partially compensate.

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%, with the schema already describing start, end, last_n, and concept. The description's note about date format normalization partially matches the schema's parameter descriptions but adds no new semantic detail beyond what is already structured. It is adequate but does not elevate above the baseline.

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 'Read-only retrieval for the narrow transparent derived series layer,' which identifies a specific verb (retrieval) and resource (derived series), and the phrase 'derived series' distinguishes it from siblings like get_economic_series. It is not a tautology, though the terms 'narrow' and 'transparent' are somewhat vague and do not fully clarify the exact scope.

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 implies usage by calling it 'read-only retrieval' and mentions the 'derived series layer,' suggesting it is for derived-series data. However, it does not explicitly state when to use this tool versus alternatives, nor does it mention exclusions or prerequisites. The guidance is implied rather than explicit.

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