calculate_activity

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

No annotations are provided, so the description carries the full burden. It discloses the unit conversion behavior (MWh→kWh, tonne→kg, gallon→litre, mile→km) and the output structure (emissions with working, GHG Protocol scope, source). This is transparent for a calculation tool with no side effects. It does not mention error handling or rate limits, but that is not critical here.

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, front-loaded with the core purpose and formula. It packs essential details (unit conversions, output, factor lookup) without redundancy. Every sentence earns its place, and it is highly scannable.

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?

Given the tool's simplicity (2 params, no output schema), the description fully covers what an agent needs: what it does, how to provide inputs, unit conversion logic, and what it returns. It also includes a prerequisite step (find factor key) and directs to appropriate tools. Without an output schema, it adequately explains return values.

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% (both parameters described), so baseline is 3. The description adds extra meaning by explaining the unit handling (converting to factor basis) and the output fields, which goes beyond just listing parameter names. It clarifies that activity is an object with value and unit, and factor_key is canonical, complementing the 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 its purpose: converting activity data into greenhouse-gas emissions using the formula emissions = activity × factor. It also details the unit conversion and what is returned (working, scope, source), distinguishing it from generic tools. The mention of finding factor keys via search_factors/lookup_factor differentiates it from specific calculation tools like calculate_electricity or calculate_freight.

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?

It provides clear usage guidance: give an amount + unit and a factor key, and explicitly instructs to use search_factors or lookup_factor to find the key. It implies this is the generic activity calculator, but does not explicitly exclude specialized alternatives like calculate_electricity or calculate_freight. Still, the workflow is well-defined.

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