variable_library_create

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

The annotations establish that this is a mutating operation (readOnlyHint: false) and not destructive (destructiveHint: false). The description adds the key behavioral trait that the call is 'long-running', which is not captured in the annotations or schema. However, it does not disclose what 'long-running' means in practice, such as whether an operation ID is returned or how the agent should monitor completion.

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 compact sentence that front-loads the action and resource, then adds the long-running caveat and optional input details in efficient order. There is no filler, repetition, or unnecessary restatement of sibling tool behavior.

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 four-parameter create tool with no output schema, the description covers what is created, where, and the optional definition-file input, and it flags the long-running behavior. It stops short of explaining the return value or follow-up polling expectations, which is a minor gap given the explicit long-running note but does not prevent a correct invocation.

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 all four parameters are already documented at the schema level. The description's parenthetical file list largely repeats the schema text for definitionDirectoryPath and omits the .platform entry, so it adds little semantic value beyond what the schema already provides.

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 states an explicit action ('Create'), a specific resource ('variable library'), and a location ('in a workspace'), making the tool's purpose immediately clear. It is easily distinguished from sibling tools like variable_library_list, variable_library_get, variable_library_update, and variable_library_delete without opening the schema.

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 identifies the creation use case and notes that providing a definition directory is optional, which helps the agent decide how to call the tool. It does not explicitly name alternatives for updating or deleting existing libraries, but the create semantics are unambiguous in this context.

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