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

With no annotations, the description carries the full burden of behavioral disclosure. It does state that the tool returns full markdown content with syntax, parameters, and examples, which is helpful. However, it does not address behavior when the function is not found, whether custom functions are excluded (beyond the phrase 'built-in'), or any other constraints, side effects, or 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 a single, well-structured sentence that front-loads the core action and resource, then provides examples and the return format. Every element earns its place, with no filler or redundant phrasing.

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 single-parameter lookup tool with no output schema, the description adequately explains the return value (full markdown content with syntax, parameters, examples) and the scope (built-in functions). It omits explicit error-handling behavior, but that is a minor gap for a simple lookup tool.

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 100%, and the schema already documents the name parameter with underscore tolerance and examples. The description adds that the function must be built-in and gives additional examples, but this is a minor enhancement over the schema rather than significant new semantic information.

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 uses a specific verb ('Find'), a precise resource ('dedicated reference page for a built-in JMeter function'), and specifies the output format ('full markdown content with syntax, parameters, and examples'). This clearly differentiates it from sibling tools like lookup_component and lookup_jmeter_property, which target different resource types.

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 establishes clear context by limiting the scope to built-in JMeter functions and providing concrete examples ('__time', '__Random', '__P'). It does not explicitly name alternatives or exclusion conditions, but the resource specificity makes it obvious when this tool is appropriate, so the context is clear enough without formal exclusions.

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