Producer price index

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

Annotations already declare read-only, idempotent, non-destructive, open-world access, so the safety profile is covered. The description adds real value beyond that by naming the returned fields (index with 100 = 1400 base, quarter-on-quarter change, point_to_point_pct, annual_pct) and the ordering guarantee, which matters since there is no output schema. It does not mention data lag or the 60-quarter cap, which would have pushed this to 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?

Front-loaded with the core purpose, then return shape, then alternatives — a logical order with no filler. The middle sentence is dense with field names but each one carries information the schema cannot.

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 two-parameter read tool with no output schema, the description covers purpose, return fields, ordering, and sibling routing, which is close to complete. Minor gaps remain around freshness/lag and the maximum quarter window, both of which affect how an agent interprets results.

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%, so both parameters (sector with its Persian enum-like values, quarters with min/max) are already fully documented in the schema. The description only restates 'by quarter and sector' and adds no format or naming guidance beyond it, so the baseline 3 applies.

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 ('Get Iran's producer price index (PPI, factory-gate prices)') plus the dimensions of retrieval (by quarter and sector, latest first). It also distinguishes itself from the detailed PPI releases that live in am_search/am_table, so an agent can tell which tool returns the headline series.

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 explicit routing: use alongside am_inflation because producer prices lead consumer prices, and use am_search('شاخص قیمت تولید کننده') + am_table for sub-sector detail instead of this tool. Both the when-to-use and the when-to-use-something-else cases are covered.

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