bw_get_variable

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

With no annotations provided, the description carries the full burden, and it excels. It discloses a significant behavioral trap: the modeling API accepts an unknown enum literal, saves its default, and still reports consistency, making create results unreliable. It also explains the limitation of query-based reading with respect to variable definitions. This is rich, non-obvious behavioral context beyond mere 'this is a getter.'

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 detailed yet tight. The first sentence states the action and scope, the second provides the usage context and the API pitfall, and the third closes with the key limitation of alternative approaches. Every sentence earns its place; there is no filler or repetition.

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 read-only tool with only two parameters, the description covers what the tool returns (an explicit list of fields), when to use it, and why alternatives fail. It does not describe the exact output structure or error cases, but given there is no output schema and the tool's scope is narrow, the description is sufficiently complete for an agent to call it correctly.

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%, so the schema already documents both parameters: variable_name as the technical name and format with its enum values and defaults. The description adds no parameter-specific details, but none are needed since the schema carries the semantic load. 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 opens with a specific verb and resource: 'Read a reusable BW Variable,' followed by an explicit list of fields (reference characteristic, description, variable type, processing type, etc.). It also distinguishes the tool from query-based reading, which resolves technical names rather than definitions, making its purpose unambiguous even among many siblings.

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 explicitly states when to use it: 'Use it after bw_create_variable to confirm what was stored.' It also explains why a create alone is insufficient, due to the modeling API silently accepting unknown enum literals, and why a query is not an alternative. This gives clear when-to-use and when-not-to-use guidance.

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