Create a new global variable

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

Discloses auto-assignment of id, auto-derivation of symbol from name with an example, and the 16-bit signed integer range. With no annotations provided, this covers important behavioral traits, though edge cases like symbol conflicts are not discussed.

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?

Three sentences, no redundant words, front-loaded with the core action. Each sentence adds distinct value: purpose, auto details, and usage guidance.

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?

Covers creation, auto-assignment, symbol derivation, variable range, and linkage to set_variable. For a simple tool with no output schema or annotations, it is reasonably complete, though it could mention uniqueness or conflict behavior.

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%, but description adds value by explaining auto-derivation of symbol and providing a concrete example ('curQ' -> 'cur_q'). This clarifies meaning beyond the schema's descriptions.

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?

Explicitly states 'Append a new Variable entry to project/variables.gbsres', which clearly identifies the resource and action. Distinguishes from sibling set_variable by noting that initial value is set separately.

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?

Provides clear context on when to use this tool vs set_variable by explaining variable range and recommending set_variable for initial value. Does not explicitly exclude other tools but differentiates from the key sibling.

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