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

Annotations already declare the read-only, idempotent, non-destructive, closed-world profile, so the bar is lower. The description adds genuinely useful behavior: results include ungraded and PSA 10 prices, but only "when known," warning the agent that price fields may be absent and that it should not assume a complete price payload.

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 short sentences: purpose and search axes first, then the return contract, then illustrative examples. Every sentence adds information and nothing is repeated from the 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?

There is no output schema, and the description compensates by stating what is returned (PokeInvest IDs plus known ungraded/PSA 10 prices). With only two fully-documented parameters and a simple read operation, nothing an agent needs to call this correctly is missing.

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%, so the limit parameter and query description are already documented, giving a baseline of 3. The description goes beyond that by demonstrating how name, set, and number combine in a single query string ("Charizard base set 4", "Umbreon VMAX 215"), which the schema's terse "optionally with set and/or number" leaves ambiguous.

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 ("Find Pokemon cards") plus the lookup axes (name, set, number) and explicitly positions itself as the entry point that returns PokeInvest IDs for the other tools. That distinguishes it from siblings like get_card_prices and identify_card_photo without the agent needing to open any schema.

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?

"Returns PokeInvest IDs to pass to the other tools" establishes the intended workflow (search here first, then use the ID with price/population/sales tools), and the example queries show the expected input shape. It does not explicitly say when to prefer a sibling such as identify_card_photo for photo input, so routing is implied rather than stated.

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