get_inventory_quantities

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

Annotations already declare readOnlyHint=true. The description adds behavioral details: it is a batch operation, returns both normal and foil counts, and requires an API key. It does not contradict annotations.

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 two sentences with no unnecessary words. It is front-loaded with the core purpose, followed by usage context and a requirement. Every sentence adds value.

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 simple batch lookup tool with a single array parameter and read-only annotation, the description covers the input, output (normal+foil counts), usage context, and authentication. It does not specify the exact output format or error behavior, but given no output schema, this is mostly sufficient.

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 description coverage is 0%, so the description must compensate. It correctly describes that the sole parameter 'cardIds' is a list of UUIDs, but adds no further detail beyond the schema's structural constraints. The description provides basic clarity but not rich semantics.

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 the verb ('return'), resource ('inventory quantities'), and scope ('normal + foil' for a batch of card UUIDs). It distinguishes itself from sibling tools like `get_card` and `list_inventory` by being a dedicated batch lookup for quantities.

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 description gives explicit context by stating 'Useful before recommending adds.' This helps the agent decide when to use it, though it does not explicitly mention when not to use it or compare with alternatives like `list_inventory`.

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