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

Annotations already provide readOnlyHint=true and openWorldHint=true, but the description adds behavioral nuance: it is query-anchored and cannot list the archive. It also describes the return fields (title, price, sale month/state, range), which adds context beyond the annotations without contradicting them.

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?

The description is two sentences. The first sentence states what the tool does and the output fields; the second provides usage guidance and a constraint. Every word earns its place, and it is front-loaded with the core purpose.

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 tool with 5 parameters and no output schema, the description covers the key behavioral aspects: what it returns, when to use it, and its query-anchored limitation. It lacks elaboration on the 'range' calculation or pagination, but the core context is sufficiently complete.

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 moderate (60%), with descriptions for q, limit, state, and country, but category has none. The description only reaffirms that q is an item description ('describe an item') and does not add meaning for the other parameters. This is baseline 3 because the schema already does most of the work.

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 tool returns individual archived sales with specific fields (title, final price, sale month/state) and the range they produce. It distinguishes from siblings by positioning it as 'the evidence rather than just the number', which differentiates it from tools like get_price_trend or get_sold_comps.

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?

It explicitly says 'Use when you want the evidence rather than just the number' and notes that the tool is 'Query-anchored — describe an item; there is no way to list the archive.' This gives clear usage context and a limitation, but does not name specific alternative tools, so it falls short of a 5.

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