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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds behavioral context by specifying the chronicle scoping and the search types (name or ID). It does not describe return format or pagination, but that is less critical given the annotation coverage and the tool's simple search nature.

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 a single, concise sentence that front-loads the action and scope. Every word adds value, and there is no fluff or unnecessary detail. It avoids redundancy with the schema and annotations.

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 search tool with no output schema, the description omits details about result structure (e.g., whether it returns a list of NPC IDs, names, or full records) and matching semantics (exact vs. partial). While the description covers the core search intent, an agent would benefit from knowing the return format and that the search is likely a partial match on name or exact ID. Given the tool's simplicity, this is a moderate gap.

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 only 33% (only the 'chronicle' parameter has a description). The description partially compensates by indicating that 'query' accepts a name or numeric ID, but it adds nothing about the 'limit' parameter. The 'chronicle' parameter's enum and description are sufficient, but the gap on 'limit' and the implicit nature of query semantics prevent a higher score.

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 verb ('search'), the resource ('NPCs'), the scope ('chronicle-scoped'), and the search criteria ('by name or numeric ID'). It also implies a workflow position with 'before opening a record', effectively distinguishing it from sibling tools like get_npc. This is a precise, unambiguous purpose statement.

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 phrase 'before opening a record' provides clear context that this tool is a precursor to fetching a specific NPC, implying get_npc as the follow-up. However, it does not explicitly name the alternative or state when not to use this tool, leaving some inference required. Still, the contextual cue is strong.

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