start_encounter

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

No annotations were provided, so the description carries full behavioral burden. It discloses that the tool writes to variants/<variant>/, leaves templates untouched, auto-generates ids, sorts combatants by initiative descending, and initializes round=1/turn_index=0. These are concrete side effects and state mutations.

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 deliver the core purpose, location, non-destructive behavior, combatant schema, and initialization details with no filler. Important constraints are front-loaded.

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?

The description covers the essential side effects, required combatant fields, sorting behavior, and initial state. With no output schema or annotations, it doesn't describe return values or error conditions, but the available information is sufficient to correctly construct and invoke the tool for the main use case.

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 0%, and the description compensates by defining the combatants item structure (name/side/initiative/ac/hp{value,max,temp?}) and explaining the variant parameter as a path segment. It does not elaborate on summary/terrain/campaign, but these are relatively self-explanatory or optional.

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?

Description uses a specific verb ('start a runtime encounter'), names the exact resource location ('variants/<variant>/'), and distinguishes itself from template editing ('doesn't touch template'). This also separates it from sibling management tools like manage_combat_state or update_campaign_state.

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?

States that it starts a runtime encounter and explicitly says it does not modify the template, which clarifies when this tool should be used as opposed to editing encounter templates. It doesn't name sibling tools or spell out when not to use it, but the 'runtime vs template' distinction provides clear context.

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