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

With no annotations, the description fully discloses behavioral traits: it aggregates sold-sale samples and vendor history, provides estimates not financial advice, and is limited to trading cards. It does not mention rate limits or auth needs, but the tool is read-only and simple.

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?

Four sentences with no fluff. The first sentence states the core function, followed by usage hints, parameter clarification, and a caveat. Every sentence earns its place.

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?

The description is thorough for a simple tool with no required parameters and no output schema. It explains the output format (chart-ready series, median per bucket, trend) and domain limitations. Minor omissions (e.g., pagination) are acceptable given low complexity.

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 parameters are well-documented. The description adds contextual value (e.g., natural-language query vs structured item, interval defaults to week) but does not significantly augment parameter semantics beyond schema.

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 clearly states the purpose: returning a chart-ready price-history series aggregated into day/week/month buckets with median and trend. It distinguishes from siblings like search_card_sales and summarize_card_market by focusing on historical price changes over time.

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?

The description explicitly tells when to use the tool (e.g., 'how has the price changed', 'price over time', trend queries, chart requests). It lacks explicit when-not-to-use or alternatives, but the sibling list and context provide indirect guidance.

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