DM20 Protocol

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

With no annotations provided, the description carries full burden and effectively discloses key behaviors: it validates slot availability, decrements slots on success, and returns remaining count. However, it lacks details on error handling, permission implications, or side effects beyond slot reduction.

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 front-loaded with the core action, uses three concise sentences with zero waste, and each sentence adds distinct value: action, validation, and return value.

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 mutation tool with no annotations or output schema, the description is reasonably complete—it covers purpose, validation, and return value. However, it lacks context on failure modes, idempotency, or how it integrates with other spell-related tools, leaving minor gaps.

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%, so the schema already documents all parameters thoroughly. The description adds no additional parameter semantics beyond implying slot_level validation, meeting the baseline for high schema coverage without extra value.

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 clearly states the tool's purpose with specific verbs ('use', 'decrementing') and resources ('spell slot', 'available slots'), and distinguishes it from siblings by focusing on spell slot consumption rather than spell management (add_spell, remove_spell) or character updates.

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 implies usage when a character needs to cast a spell requiring a slot, but provides no explicit guidance on when to use this tool versus alternatives like 'roll_dice' for casting or 'apply_effect' for spell effects, nor does it mention prerequisites like character existence.

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