set_variable_name

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

With no annotations, the description carries full behavioral burden. It discloses two important side effects: growing the variable list when the id is past the end, and that naming makes the variable visible to the next session. It could mention more (e.g., renaming behavior, uniqueness), but the disclosed traits are valuable and non-obvious.

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, each earning its place. The first states the action, the second explains a key side effect, and the third gives practical usage guidance. No fluff or redundant information.

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 setter with well-documented schema, the description covers the essential behavioral nuances (list growth, session visibility) and usage timing. It does not mention return values, but no output schema is needed for a write operation and the description is sufficiently complete for an agent to use 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 coverage is 100% for all parameters, so the baseline is 3. The description adds context about variableId coming from next_free_id, but does not explain the parameters themselves 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 opens with 'Set a variable name,' which is a specific verb+resource statement. It distinguishes itself from siblings like set_switch_name by clearly targeting variables and adds context about the variable list.

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 advises naming a variable immediately after claiming it via next_free_id, and references list_allocated_ids for visibility across sessions. It clearly implies when to use the tool, though it does not explicitly mention alternatives or when not to use it.

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