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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely new context: provenance (twice-monthly USDA MARS production cost reports), 'no API key', and result ordering ('oldest first'), which the annotations do not convey. Rate limits or per-report field detail are absent, keeping it short of a 5.

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?

Three sentences ordered purpose → usage/alternative → behavior, each carrying distinct information. No filler, and the purpose 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?

With no output schema, the description still tells the agent what comes back (a sequence of report periods, oldest first, bounded by `periods`) and where the data originates. It stops short of describing the per-report fields, which is the main remaining unknown for a history tool.

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 the baseline is 3; the description nonetheless adds meaning the schema lacks, notably the 'oldest first' ordering of the returned periods and the 'roughly two years' framing of max 52. It repeats default/max from the schema rather than extending it further.

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?

States a specific verb and resource ('Price history for one fertilizer product across report periods') and immediately identifies the data source. It explicitly distinguishes itself from the sibling get_fertilizer_price, so an agent can route correctly without opening either schema.

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?

Gives both directions explicitly: 'Use for input-cost trends' and 'use get_fertilizer_price instead when only the latest quote matters.' The alternative and the condition that selects it are named, leaving nothing to inference.

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