svar_set

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

No annotations are provided, so the description carries the behavioral burden. It usefully discloses the value encoding convention: scalars as plain strings and arrays as JSON array strings, with a concrete example. It does not discuss overwrite behavior or errors, but the key calling convention is covered.

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?

Two sentences with no wasted words. The main action is front-loaded, and the critical serialization guidance is provided immediately after, with a clear example.

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 simple two-parameter setter, the description and schema together provide enough to invoke it correctly: target path and value format are both covered. There is no output schema, but a setter's return value is not essential for correct use. Edge cases like nonexistent variables are not addressed, but they are not critical to basic 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?

The schema documents var_path as 'Full path' but gives no description for value. The description compensates by fully explaining how to encode scalar and array values, which is the non-obvious part. var_path is adequately covered by the schema itself.

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 and resource: 'Set a Setup variable value.' It clearly identifies the target as a Setup variable, distinguishing it from sibling setters like dvar_set, mvar_set, and instrvar_set.

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 phrase 'Setup variable' provides clear context about which variable family this tool applies to. It does not explicitly name alternatives or exclusions, but the target domain is clear enough for an agent to route correctly among the many setter tools.

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