Evaluate the value an expression approaches as a variable nears a point, including one-sided or two-sided directions.
Limit of expression as variable -> point (oo allowed).
direction: "+" (right), "-" (left) or "+-" (two-sided).
| Name | Required | Description | Default |
|---|---|---|---|
| point | No | 0 | |
| variable | No | x | |
| direction | No | + | |
| expression | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It notes that infinity ('oo') is allowed as a point and defines direction semantics, but it omits whether computation is symbolic or numeric, how divergent limits are handled, or any error conditions.
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 compact sentences that front-load the operation and then explain the direction parameter. Every phrase carries information, and there is no redundant or filler text.
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?
An output schema exists, so return values need not be described. The description covers the purpose and parameter meanings adequately, but with no annotations and 0% schema coverage it lacks usage guidance and behavioral edge-case information that an agent might need to invoke it correctly in context.
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?
With 0% schema description coverage, the description must explain all four parameters. It clarifies the roles of expression, variable, point, and direction, including the allowed direction values and the acceptance of infinity for the point.
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 gives a precise mathematical verb and resource: computing the limit of an expression as a variable approaches a point. It is immediately distinguishable from siblings such as differentiate, integrate, or evaluate, which perform different operations.
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 explains the direction argument but offers no guidance on when to use this tool versus alternatives like evaluate or solve_symbolic_equation. It also does not specify prerequisites or contexts where a limit is preferable.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.