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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, so the safety profile is covered. The description adds useful scope detail beyond that: results are per-printing, prices are today's market in USD, and the move window is 90 days — the kind of context 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?

A single sentence with zero filler, front-loading the trigger condition ("after `search`") followed by the payload the tool returns. Nothing redundant.

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?

With an output schema present, annotations covering safety, and one required param, the description is complete enough to call the tool correctly. The only remaining gap is not clarifying how this differs from the `card_price` and `price_history` siblings.

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% and the single `id` parameter is already documented as "Product id from `search` results." The description repeats the same provenance hint without adding format or edge-case detail, so the schema is doing the heavy lifting.

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 (read) and resource (one product) and enumerates exactly what comes back: today's market price per printing in USD, 90-day move, and page URL. It clearly distinguishes itself from `search`, but does not distinguish itself from the sibling `card_price`, which sounds like it offers overlapping capability.

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?

"Use this after `search`" gives an explicit sequencing rule and tells the agent the id must come from a prior search. It stops short of any when-not guidance or pointing at `card_price`/`price_history` as alternatives for other price needs.

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