calculate_pet_calories

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

With no annotations, the description carries the full burden, and it does well: it reveals the underlying formula, the multiplier basis (WSAVA/AAHA-style), the fact that results include RER/DER/budget/treat allowance, and an output-citation obligation. It doesn't explicitly state this is a pure, side-effect-free computation, but for a calculator the formula disclosure is the material behavioral detail.

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 dense sentences, front-loaded with the purpose and formula, then outputs, then the citation rule. Every sentence carries information, though the inline formula slightly interrupts the prose flow.

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?

With no output schema, the description correctly enumerates the return fields (RER, DER, daily budget, treat allowance, optional food grams), which is what an agent needs. It could go further on output units (kcal vs grams) and assumptions, but nothing essential 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 description coverage is 75%, so the schema already documents most inputs including defaults for neutered, weightUnit, targetWeight, and activityLevel. The description adds only tangential meaning (linking foodKcalPer100g to the optional grams/day output) and explains none of the enums or unit interactions in more depth.

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 (Estimate), a precise resource (daily calories for a cat or dog), and even names the method (RER = 70 × kg^0.75 with MER/DER multipliers). This is unambiguously distinct from siblings like lookup_ideal_weight or convert_cup_to_grams.

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?

Usage is implied by the mention of defaults and the optional food-grams parameter, but there is no explicit when-to-use / when-not-to-use guidance and no routing to or away from the sibling tools. The one concrete rule given ('Always cite sourceUrl') is useful but narrow.

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