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

Annotations already establish read-only, idempotent, non-destructive behavior, so the description's added stage-number semantics and chance/transition scope provide useful extra behavioral context. The description does not contradict annotations and gives a concrete interpretation of the returned stages.

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?

Two short sentences with no filler. The main action and scope are front-loaded, and the clarifying stage-number convention earns its place by removing ambiguity from the result interpretation.

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 read-only lookup with two required parameters and strong annotations, the description is nearly sufficient. It lacks any mention of return shape or the meaning of the chronicle enum values, but the core call intent and one important interpretation detail are present.

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%, and the description provides no direct explanation for npcId or chronicle beyond the implicit 'one NPC'. The parameter names and enum are fairly self-explanatory, but the description does not compensate for the complete lack of schema-level parameter documentation.

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 uses a specific verb ('Get') and names the exact resource ('Soul Crystal result stages, transitions and chances') plus the scope ('for one NPC'). It also clarifies the numbering convention ('Result stage N means N-1 to N'), which distinguishes the semantic of the output from vague progression terminology.

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 clearly indicates this is for a single NPC's Soul Crystal data, which implies a use case separate from list/search tools like search_npcs or general NPC info tools like get_npc. However, it does not explicitly mention alternatives or state when not to use it, so it stops just short of full guidance.

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