calculate_stack

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

With no annotations provided, the description carries the full transparency burden. It only states the high-level operation without disclosing side effects, error handling, read-only status, or the computation logic. The phrase 'Sum' implies a read operation, but key behavioral details are absent.

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 a single sentence with no redundant words, front-loading the action verb 'Sum'. It is appropriately sized for a simple tool, though brevity limits explanatory depth.

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?

Despite having an output schema and a nested input structure, the description omits important context such as return value, usage scenarios, and integration with sibling tools. It fails to mention that multiple product selections can be summed, leaving the tool's full capabilities unclear.

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 vaguely mentions 'product and serving combination' but does not clarify the roles of product_id or servings_per_day, nor that selections is an array allowing multiple entries. This adds minimal value beyond the raw schema.

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's action ('Sum') and resource ('known label amounts') for a specific context (product and serving combination). It distinguishes itself from sibling tools like search_products and get_product by using a calculation-oriented verb, avoiding tautology.

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 implies usage for totaling label amounts, but provides no explicit guidance on when to use this tool versus alternatives. It does not mention sibling tools or any exclusions, leaving usage context largely inferred.

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