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

Annotations already establish readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that — that the call is free, fixed to Q1 2019, and available at daily or weekly granularity — but says nothing about rate limits, result size, or response format.

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?

A single dense sentence with the scope and the value proposition front-loaded and no filler. Slightly clipped to the point of being a fragment, which costs a little clarity, but nothing is wasted.

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 one-parameter, no-output-schema tool this covers the data scope and cost, which is most of what an agent needs. However, it offers no way to know how daily versus weekly output is selected when no such parameter exists, leaving an actionable ambiguity unresolved.

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% and the single 'company' parameter is fully documented in the schema (ticker:, ISIN, isin: forms). The description adds nothing about the parameter, 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?

The description names the resource and its scope concretely: Q1 2019 sales, units and panel stores for one company. It is clear this returns a preview dataset rather than an analysis, which separates it from get_yoy_growth and quote_sales, though it never uses an explicit verb like 'retrieve' and doesn't name those siblings directly.

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?

'Free, to see what the data looks like' implies the intended use case (data preview before committing to a paid/larger query), but there is no explicit when-to-use/when-not guidance or reference to the sibling tools that would serve the follow-up need. Usage is inferable but not stated.

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