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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and network scope are covered. The description adds real value by disclosing that the population report spans every grading company and grade Alt tracks and that a raw sales feed is included, clarifying the scope of returned data. It says nothing about pagination, freshness, or rate limits, so it does not go beyond the structured fields substantially.

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?

Two sentences, no filler, with the payload contents front-loaded and the parameter provenance in the trailing sentence. Efficient and well ordered, though the first sentence is dense with comma-separated clauses.

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?

An output schema exists, so return values need not be spelled out, yet the description still summarizes them usefully. Combined with the annotation-declared safety profile and the parameter provenance, an agent has everything needed to invoke it correctly; only freshness/limit behavior is unaddressed.

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?

With schema description coverage at 100% and a single fully documented parameter, the schema already carries the semantics. The description's restatement that asset_id comes from a prior search result duplicates the schema's own description rather than adding syntax or format detail. 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 (one card design's identity) and enumerates the payload it returns: a population report across grading companies and a raw sales feed. That is concrete enough that an agent can distinguish it from list/search siblings like alt_search and alt_sold_listings. It stops short of a crisp verb, but the retrieval nature is unambiguous.

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 states the prerequisite: asset_id comes from a prior alt_search/alt_sold_listings/alt_card_search result, which tells the agent this is a follow-up detail call rather than an entry point. It does not say when to prefer it over the sibling alt_listing, but the dependency routing is clear.

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