roll_check

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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false. The description adds real context beyond them: that purpose/difficulty/stakes are fixed, that a purpose cannot be rerolled, and that the complete check set plus a context hash are returned. That is useful behavioral detail for a persistence tool.

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 tight sentences with the core action front-loaded, followed by the immutability rule and the return summary. No wasted words, though the sentences are terse to the point of under-explaining the missing parameters.

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 10-parameter mutation tool with no output schema, the description helpfully summarizes the return value. However, it is far too thin for the parameter surface, leaving most required fields unexplained, so an agent cannot call it correctly from the definition alone.

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 0% across 10 parameters (8 required), so the description carries the full burden. It names only purpose, difficulty and stakes, leaving campaign_id, branch_id, preparation_id, check_id, attribute, basis and situational entirely undocumented in both schema and description.

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: 'Persist a server d20 result' with the fixed attributes (purpose, difficulty, stakes). It is clear what the tool does, though it does not explicitly differentiate itself from siblings like preview_world or get_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?

Offers only a single constraint ('No rerolling a purpose') rather than guidance on when to call this versus alternatives. There is no mention of prerequisites (e.g., needing a preparation or branch first) or when-not-to-use, leaving usage to inference.

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