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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's job is to add beyond that. It does: values retain Portuguese display formatting (a non-obvious output quirk) and pagination continues via next_cursor, both of which the annotations cannot express.

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 tight sentences, front-loaded with the verb and resource, then behavior, then pagination. No filler and nothing redundant with the schema.

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?

An output schema exists, so return-value detail is unnecessary, and the description supplies the two non-schema facts an agent needs (formatting quirk, cursor continuation). It stops just short of noting the origin of chart_id or the cursor/offset trade-off.

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 limit, cursor, offset and chart_id all documented in the schema itself, so the baseline is 3. The description only echoes pagination via the response field name 'next_cursor' and adds no syntax or selection guidance for limit vs cursor vs legacy offset.

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 ('Retrieve') and resource ('a published chart'), then enumerates the payload contents (values, units, comparison, period, population, source, methodology). This clearly separates it from list_charts, which only enumerates chart identifiers, though the sibling get_citation is never addressed.

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?

Usage is only implied: get a chart by id, and follow next_cursor for further rows. There is no explicit when-to-use versus list_charts/get_citation, no prerequisites (e.g. that chart_id must come from list_charts), and no exclusions.

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