mode

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 basic behavior (finding the mode and returning all most frequent values), but lacks critical details such as how it handles empty lists, ties, non-numeric inputs (since the schema expects strings), error conditions, or performance characteristics. For a tool with no annotations, 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 extremely concise and front-loaded, with two sentences that directly state the purpose and return behavior. Every word earns its place, and there is no redundancy or unnecessary information. The parenthetical domain/category note is brief and relevant.

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 moderate complexity (statistical operation with one parameter), no annotations, no output schema, and 0% schema description coverage, the description is incomplete. It lacks details on input handling, error cases, output format (beyond a high-level description), and practical usage context. The absence of structured support makes the description insufficient for reliable agent invocation.

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 mentions 'a list of numbers' for the 'numbers' parameter, but does not explain that the schema expects strings (not numbers), clarify formatting (e.g., comma-separated, numeric strings), or detail constraints (e.g., minimum list length, allowed numeric formats). This adds minimal semantic value beyond the schema's type definition.

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 verb ('Find') and resource ('mode in a list of numbers'), specifies the exact mathematical operation, and distinguishes it from siblings by focusing on statistical mode calculation rather than other mathematical functions like mean, median, or trigonometric operations. It explicitly mentions the return behavior ('Returns all values that appear most frequently'), which is precise.

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 ('statistics') and category ('general'), but does not specify scenarios where mode is preferred over other central tendency measures (e.g., mean or median), nor does it reference sibling tools for related operations. Usage is implied only by the tool's name and purpose.

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