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

Beyond the annotations (readOnly, idempotent, non-destructive), it discloses that prices are raw/ungraded only, are not an appraisal of a specific copy, are denominated in USD, and carry a price date. It also names the returned `headline` field and the page URL, giving the agent real behavioral context the structured fields do not.

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?

Three sentences, front-loaded with the usage trigger, then the return shape, then the limitation and prerequisite. Every sentence carries distinct information with no repetition.

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, yet the description still usefully previews the key return fields and the raw-only caveat. Combined with the explicit prerequisite and the price-date disclosure, an agent has everything needed to call it correctly for a single-parameter read tool.

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 schema already says the parameter is a 'TickerMint product_id from search_cards,' so the description's 'Needs a product_id from search_cards' mostly restates it. Baseline 3 applies since the schema does the heavy lifting; the description adds no format or edge-case detail beyond the origin.

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 and resource — pricing one specific card or sealed product for today — and immediately narrows the scope to the 'latest daily' TCGplayer market/lowest listed price per printing. It is readily distinguishable from siblings like price_history (historical), set_prices, and sealed_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?

The trigger is explicit: 'Use this when the user asks what one specific card or sealed product is worth today,' and the prerequisite 'Needs a product_id from search_cards' routes the agent to the right preceding call. It lacks an explicit exclusion sentence (e.g., 'for trends over time use price_history'), leaving that contrast implied by the word 'today.'

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