Get current active character

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

The description discloses that the result may be inferred from death/level_up log lines and includes a warning to check the 'source' field ('explicit' vs 'inferred_from_log' vs 'none'). This adds significant behavioral detail beyond the readOnlyHint annotation, which only indicates it's a read operation.

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, information-dense sentence that front-loads the core purpose, then explains the inference mechanism and the caution about the source field. No redundancy or fluff.

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 zero-parameter read-only tool, the description covers the key behavior and the important source field. It doesn't detail the full return structure, but given no output schema and the simple nature of the tool, it's sufficient.

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?

There are no parameters, so the baseline is 4 per rubric. The description adds context about the return value's source field, which is useful, but there is nothing to add about parameters themselves.

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 precisely states the tool's function: returning the default character used by other tools when characterName is omitted, and explicitly names four sibling tools (get_passive_tree, get_defenses, get_offense_stats, compare_item). This clearly differentiates it from siblings like set_active_character.

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?

It explains the tool's role in the context of other tools and advises checking the 'source' field before trusting the result. It doesn't explicitly state when not to use it or name alternatives, but the context makes its purpose evident.

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