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

readOnlyHint=true already establishes the safety profile, so the description's remaining burden is light. It adds genuinely useful substance by disclosing that limits and publish-retention eligibility are surfaced here, but says nothing about volume, size, latency, or how the catalog is shaped.

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 front-loaded sentence with no preamble or filler; the most decision-relevant content ('List available price data') comes first. The trailing enumerated list is dense but every item adds information about what the agent will learn.

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 zero-parameter, read-only discovery tool with no output schema, the description must carry the return-value burden, and it does name the categories returned (fields, dates, limits, retention eligibility). It stops short of describing how the catalog is organized or what an agent should do with 'limits', which is the one remaining gap.

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?

The tool takes zero parameters, so there is no argument semantics to explain and the baseline of 4 applies. Nothing in the description misdescribes the (empty) input contract.

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 pairs the verb 'List' with a concrete catalog of what is enumerated: price data, fields, dates, limits, and report-retention eligibility. That tells an agent this is a discovery/metadata tool rather than a data-fetch tool, though it never names a sibling such as get_prices or build_series to make the boundary explicit.

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: an agent can infer this is the upfront 'what is available here' call before build_series or get_prices, but the description never states when to call it, when not to, or which sibling to prefer once the available dates/fields are known.

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