percentage

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions 'exact' implying no rounding, but does not describe the output format, error handling (e.g., total=0), or any side effects. This is insufficient for a tool with no structured metadata, leaving the agent guessing about the return type and edge cases.

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, compact sentence of eight words. It front-loads the core function and includes the key constraint (rationals accepted) without any redundant wording. Perfectly concise and well-structured.

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 two-parameter calculation tool, the description is mostly adequate, but it leaves important context missing. It does not specify the output format (e.g., decimal, percentage string) or how to handle invalid inputs like zero total. These omissions could lead to incorrect invocation or misinterpretation of results, making it slightly incomplete.

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 parameter descriptions are non-existent (0% coverage), so the description must compensate. It does by clearly mapping 'PART' and 'TOTAL' to the parameters and explaining their relationship via the division formula. The note about accepting rationals adds semantic detail that is not present in the schema, making the parameters more understandable.

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 computes an exact share and percentage from PART/TOTAL. It uses a specific verb-implicit calculation and distinguishes from sibling 'percentiles', which deals with distribution percentiles. The inclusion of 'rationals accepted' adds precision to the input domain, making the purpose 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 gives clear context that this tool is used when a percentage or share of two numbers is needed. However, it does not explicitly mention alternatives or when not to use it, so it lacks explicit exclusions but provides enough contextual clarity for typical use.

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