Roll initiative

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

Annotations already flag destructiveHint and non-idempotent behavior, and the description adds meaningful behavioral detail: rolls are only posted to chat when toChat is enabled, and hidden combatants are never posted publicly. It also clarifies the default of rolling only for combatants missing initiative. No contradiction with annotations is present.

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 short sentences, each adding distinct value: purpose and scope, default filtering behavior, and chat/privacy behavior. There is no filler, no repetition of schema field names, and the most important information is 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?

For a 7-parameter tool, the description plus fully covered schema is sufficient: core behavior, scope defaults, and privacy constraints are disclosed. It doesn't describe return values, but there is no output schema, and the main calling decisions—scope, toChat, combatId, and rollMode—are covered either in the description or the input schema.

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 description coverage is 100%, which satisfies the baseline, and the description goes further by explaining the meaning of scope ('all', 'non player characters', 'combatants named'), onlyMissing ('only those without initiative roll'), and toChat ('posted to the chat only with toChat'). formula, combatId, and rollMode are left to the schema, which already documents them adequately.

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 names a specific action ('Roll initiative'), a target (combatants), and the source of the formula (the game system's formula), and it lays out scope variants: all, NPCs, or named combatants. It doesn't explicitly distinguish itself from sibling tools like roll-dice or roll-actor-check, but the combatant-and-initiative focus makes the purpose clear.

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 gives useful context for when this tool is relevant—initiative rolls in combat—and states defaults such as only rolling for combatants without initiative and not posting to chat unless toChat is set. It does not name alternatives or give explicit when-not-to-use guidance versus roll-dice/roll-actor-check, so usage guidance is implied rather than explicit.

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