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

With no annotations, the description carries the full behavioral burden. It discloses that values are asks rather than sold prices, that asks are a ceiling, and that the data is free, refreshed daily, sourced from eBay enrichment, and merkle-committed. This gives an agent a strong safety and trust profile.

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 dense but front-loaded: the core scope and price-basis caveat come first, followed by freshness, source, value-layer role, and usage triggers. Some phrasing repeats the loan-terms point, but the length is justified given there are no annotations or output schema.

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 one-parameter read-only tool with no output schema, the description covers the payload fields, price semantics, refresh cadence, source, cost, and typical queries. It also explains how to get product_id and when to call it in the loan-term workflow, leaving little for the agent to infer.

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 0% and the only parameter has just a title, but the description explicitly defines product_id as the TCGplayer id from search. This resolves the key ambiguity about how to obtain and supply the identifier.

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 what the tool returns: PSA/BGS/CGC median asking prices for one card, broken out by grade with listing counts, low/high, an as-of date, and an explicit price_basis. It also distinguishes itself from siblings and sold-price tools by emphasizing these are eBay asks, not sold prices.

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 includes an explicit 'Use this when' section with concrete query examples like 'what does a PSA 10 of this go for?' and 'raw vs graded premium?', and positions it before loan_terms_preview. It does not explicitly list alternatives to avoid, but the usage context is clear and actionable.

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