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

Annotations already declare this read-only, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context: the response is cached for one hour, and it enumerates exactly what is returned (costs, up to ten durability entries per damage type, all grades Twig to Armored). It does not say what happens for a missing slug, which keeps it from a 5.

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 content is dense but mostly earns its place, since field-level detail substitutes for a missing output schema. The opening sentence merely restates the title, and the rest is a single long run-on enumeration rather than being clearly partitioned by cost/durability/siblings.

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?

With no output schema, the description carries the return-value burden and does so thoroughly, including nested cost shapes (`amount` vs `min_amount`/`max_amount`) and the durability list caps. What is missing is failure behavior and sibling differentiation, both of which matter for correct invocation.

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?

Only one parameter and the schema already documents it at 100% coverage, including the `stone-wall` example and the pointer to `/building`. The description adds nothing about the slug format or constraints, so it sits at the baseline for a fully-documented schema.

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 makes clear this is a single-piece lookup keyed by slug, returning costs, durability and grade siblings. That is a specific resource with a specific payload. It does not explicitly distinguish itself from related siblings like get_raid_costs or get_upkeep_rules, so an agent must infer the boundary.

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?

There is no statement of when to call this versus get_raid_costs, get_upkeep_rules or get_world_entity, and no prerequisites or error conditions (e.g. unknown slug). The only usage-adjacent note is the one-hour cache. The agent gets payload detail but no routing guidance.

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