get_inventory_quantities

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

No annotations are provided, so the description carries the burden. It adds behavioral context by stating 'Requires IWMM_API_KEY,' which informs about authentication needs. However, it does not disclose whether the operation is destructive, rate limits, or other traits. This is adequate but not comprehensive.

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 concise, consisting of three short sentences each adding value: purpose, use case, and requirement. It is front-loaded with the core functionality and avoids unnecessary elaboration.

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?

The tool is simple with one parameter and no output schema. The description explains what the tool returns (counts per card with normal/foil distinction) but does not specify the response format (e.g., map or list, keys). It also lacks error handling or edge case information. This is acceptable for a straightforward read operation but could be more complete.

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?

The description adds minimal meaning beyond the input schema. It says 'given a list of card UUIDs,' which essentially repeats the schema's field name and type. With 0% schema description coverage, the description should provide more parameter details, such as format or constraints, but it does not.

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?

Description clearly states 'Batch lookup: given a list of card UUIDs, return how many of each (normal + foil) the user owns.' It uses a specific verb ('batch lookup') and resource ('inventory quantities'), distinguishing it from sibling tools like list_inventory (which lists all inventory) and add_inventory.

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 provides a clear use case: 'Useful before recommending adds.' This helps the agent understand when to use the tool. However, it does not explicitly mention when not to use it or alternatives, which would improve the score.

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