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

The description discloses the key side effect beyond the annotations: it 'marks result as drawn (for no-replacement tables)' and 'shows in Foundry chat.' This is valuable because readOnlyHint is false and an agent needs to know the call mutates table state. There is no contradiction with destructiveHint=false, since marking a result drawn is not destructive deletion.

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 with no wasted words: the core action, the side-effect behavior, and the prerequisite are each clearly and concisely stated. The description is front-loaded with the primary purpose.

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 two-parameter tool with full schema coverage, the description covers the action, side effects, and prerequisite. There is no output schema, but the description adequately conveys that the result is a random table result. It could mention edge cases like an exhausted no-replacement table, but that is minor given roll-table-reset exists as a sibling.

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% and both parameters already have clear descriptions: tableId is the 'Roll table ID' and displayChat controls chat display with a default. The description adds a small hint about finding tableId via roll-table-list, but otherwise does not enrich parameter meaning beyond the schema.

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?

States a specific verb and resource: 'Roll on a table and get random result.' It also distinguishes itself from sibling roll-table tools by referencing table.draw() and the Foundry chat display, so an agent can tell it apart from roll-table-create/get/list/reset/update.

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?

Gives clear usage context: use this when you want a random result from a table. It explicitly provides the prerequisite step, 'Use roll-table-list to find the table ID,' which is practical and actionable. It does not explicitly name alternatives or when-not-to-use cases, but the context is sufficient for selection.

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