update_buy_list

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

Given no annotations, the description carries full burden. It clearly states the tool sets absolute quantity (overwrites existing) and that 0 removes the row. This is sufficient for a simple update. However, it could mention idempotency or that it only affects the specified finish. Still, the disclosed behavior is clear and accurate.

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, each purposeful. The first sentence states the core function, the second clarifies a special value, the third gives guidance and prerequisite. No wasted words, front-loaded with key action.

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 write operation with 3 parameters and no output schema, the description covers all needed context: what it does, how quantity works, when to use alternative, and a prerequisite. It is complete for an agent to decide and invoke correctly.

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%, but the description adds value beyond the schema: for cardId it says 'Internal IWMM card UUID. Get from search_cards or get_card.' For isFoil it adds context about separate rows and default. This extra information aids correct parameter usage, justifying a score above baseline 3.

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 tool sets absolute quantity for a buy-list card+finish, not a delta. It distinguishes itself from add_buy_list and explicitly notes that quantity 0 removes the row. The verb 'set' and resource 'buy-list card+finish' are specific and unambiguous.

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 explicitly tells when to use this tool vs the alternative: 'Use add_buy_list to increment instead.' It also mentions a prerequisite: 'Requires IWMM_API_KEY.' This provides clear guidance on appropriate use.

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