Character Hitdice Spend

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

With destructive/non-idempotent annotations already set, the description adds real value: async dispatch semantics (sent:true,confirmed:false,status:"pending" is not a business ACK), no shared transaction with healing, no reliable capability probe, older servers silently ignoring the event, and retry guidance via events_poll. However, the corrupted sentence "there is no v1.5.0 permits the owner or DM but never a spectator" is incoherent and leaves the gating model ambiguous.

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 critical spend/async/retry information is reasonably front-loaded, but the description is long for two parameters and contains a broken, self-contradicting sentence about gating that costs reader comprehension. Some hedging ("no reliable capability probe," "may silently ignore") earns its place, but the corrupted line does not.

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?

Given a destructive mutation tool with an output schema and full annotations, the description covers auth requirements, async result handling, error shapes ({ok:false,error} vs MCP argument errors), and retry discipline. The only real gap is the garbled gating sentence, which leaves the spectator/permission model unclear.

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%, so the baseline is 3, but the description adds a useful anti-pattern clarification that index "selects an array entry, not a dice count," plus the guidance to inspect character_get for valid pools and remaining uses. This meaningfully supplements the schema without contradicting it.

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 opening sentence gives a specific verb+resource+scope: "Spend one remaining use from a DND_5E character's Hit Dice pool through WS." It explicitly distinguishes itself from roll/heal siblings (dice_roll, token_hp_update). The trailing garbled sentence about gating slightly muddies the otherwise clear purpose, so it falls short of a clean 5.

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?

It names prerequisites (owner or DM, campaign assignment), routes the agent to character_get for inspection, and clarifies that dice_roll/token_hp_update handle rolling and healing separately with no shared transaction. It also prescribes post-call behavior (read events_poll before further action, never blindly resend). It stops short of an explicit when-not-to-use rule, so 4 rather than 5.

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