create_data_stream

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

With no annotations, the description carries the full behavioral burden, and it does disclose the key precondition that an index template must pre-exist. Beyond that it says nothing about required permissions, failure behavior, or whether creation is idempotent, so the disclosure is thin.

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 first and second sentences are redundant ('Create a new data stream' vs 'This creates a new data stream with the specified name'), with no additional information in the second. The prerequisite sentence is the only one that earns its place.

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 explained, and the parameter schema is fully described. The remaining gap is behavioral/usage context — failure modes and differentiation from sibling creation tools — which leaves it only minimally viable.

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 coverage is 100% with both parameters documented (name, optional cluster), so the schema does the heavy lifting. The description adds no syntax or format meaning beyond what the schema already states; baseline 3 applies.

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?

States a specific verb and resource ('Create a new data stream'), so the operation is unambiguous. However, it does nothing to distinguish itself from siblings like create_index or index_document, and the second sentence merely restates the first.

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?

It gives one real precondition ('must have a matching index template before creation'), which is useful context. But it offers no guidance on when to choose this over create_index or how it relates to the data-stream siblings.

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