set_encounters

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

With no annotations, the description carries the burden of behavioral disclosure. It clearly states that the list is replaced wholesale, that every troopId is validated against Troops.json, and that a non-existent troop throws. It also explains the 'hides the on-disk shape' aspect. However, it does not mention the return value (e.g., success indicator) or the effect of dryRun, though the schema covers dryRun separately.

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 three sentences: first the main action, then the encounter object format, then validation and tool preference. Every sentence adds essential information without redundancy. It is front-loaded with the primary purpose and avoids tangents.

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 the tool's moderate complexity (encounter list with nested objects) and lack of output schema, the description fully prepares the agent to invoke it correctly: it covers the operation, parameter semantics, validation, defaults, and the recommended alternative. All necessary context for selection and use is 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 provides baseline descriptions for all parameters, but the description adds significant meaning beyond schema: weight's default value (5), regionSet's empty/omitted interpretation ('anywhere'), validation behavior for troopId, and the meaning of encounterStep ('average steps between encounters'). This enriches the schema's parameter definitions with practical semantics.

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 function: 'Set a map's random-encounter list (replaces it wholesale) and optionally its encounterStep.' It uses a specific verb ('Set') and resource ('map's random-encounter list'), and explicitly differentiates from the sibling tool update_map by recommending this for encounters, preventing confusion.

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 provides explicit usage guidance: 'Prefer this over update_map for encounters (it validates and hides the on-disk shape).' This tells the agent exactly when to use this tool versus an alternative, and implies it is the appropriate choice for encounter list changes.

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