harmonic_number_fraction

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

No annotations are provided, so the description carries full behavioral disclosure burden. It states the tool 'returns as fraction,' which is useful behavioral information about output format. However, it doesn't mention computational characteristics (e.g., performance with large n, precision limitations, memory usage), error conditions, or whether n must be positive. For a mathematical tool with no annotation coverage, this leaves significant behavioral gaps.

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 concise and front-loaded with the core functionality in the first clause. The parenthetical domain/category information is secondary but potentially useful. No wasted words, though it could be slightly more informative without losing conciseness.

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 no annotations, no output schema, and 0% schema description coverage for the single parameter, the description is incomplete. It explains what the tool does and the return format but lacks crucial context: parameter semantics, computational behavior, error handling, and differentiation from sibling tools. For a mathematical calculation tool, users need more guidance about valid inputs and expected behavior.

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?

The input schema has 1 parameter (n) with 0% description coverage. The description doesn't explicitly mention the parameter or add any semantic context beyond what's implied by 'harmonic number' (n is typically a positive integer index). Since schema coverage is 0%, the description should compensate more by explaining parameter meaning, constraints, or examples, but it only provides minimal implicit context.

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 purpose: 'Calculate harmonic number using exact fractions (returns as fraction).' It specifies the verb ('calculate'), resource ('harmonic number'), and method ('exact fractions'), distinguishing it from generic harmonic number calculations. However, it doesn't explicitly differentiate from sibling tools like 'harmonic_number' or 'harmonic_partial_sum', which slightly reduces clarity.

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 provides no guidance on when to use this tool versus alternatives. It mentions the domain ('arithmetic') and category ('harmonic_series'), but doesn't explain when to choose this exact-fraction method over other harmonic number tools or mathematical approaches. No explicit when/when-not instructions or sibling tool comparisons are present.

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