lambda_invoke

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 states the tool invokes a function and returns the response, but lacks details on synchronous behavior, error handling, or what happens with different invocation types. This is minimal but not misleading.

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, focused sentence with no filler. It front-loads the action ('Invoke a Lambda function') and adds necessary context ('LocalStack', 'return its response').

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 relatively simple tool with 100% schema coverage, the description adequately covers the main purpose. It does not describe return value structure, but no output schema exists, and the invocationType enum covers other invocation modes. Some additional behavioral details could improve it, but it's reasonably complete.

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?

Input schema description coverage is 100%, so all three parameters (payload, functionName, invocationType) are already documented. The description adds no additional parameter semantics, so baseline 3 is appropriate.

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 ('Invoke') and resource ('Lambda function'), includes the LocalStack context, and states it returns the response. This clearly distinguishes it from sibling tools, which cover other AWS services.

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 clearly implies when to use this tool: when you need to invoke a Lambda function and get its response. No explicit exclusions or alternative tools are mentioned, but siblings are unrelated services, so this provides adequate guidance for the intended use case.

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