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

Annotations already declare destructive/non-idempotent/openWorld, and the description adds genuinely new semantics: omitted fields are preserved (PATCH-like merge), a sent list replaces the stored list, uploaded files are exempt from replacement, and a larger size raises hourly cost. It does not mention the destructive resetWorld path or permission requirements, which a mutating tool of this weight could use.

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?

Three sentences, each earning its place: scope first, then merge/replace semantics, then exclusions and the restart/cost consequence. Zero boilerplate and the operative constraint is front-loaded.

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 destructive bulk-update tool with a large nested body and no output schema, the description covers merge semantics, side effects (restart requirement), cost, and sibling exclusions. It leaves the safety-critical resetWorld and domain verification steps to the schema rather than surfacing them, which is the remaining 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?

Reported schema coverage is 0% at the top level and the body is a deeply nested object, so the description carries some burden; it clarifies merge/replace behavior and the cost implication of `size`, which the schema does not. However it does not explain the individual config fields, resetWorld, or customDomain beyond what the schema already says, so it does not compensate for the structural complexity.

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?

States a specific verb (changes) and enumerates the resource facets it touches: name, size, settings, player lists, content, auto-start, custom domain. It also names the two siblings it is *not* (setResourcePack, resetServer), so an agent can discriminate without opening schemas.

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?

Explicit exclusions with the correct alternative tools are given ('Not for the resource pack (setResourcePack) or a fresh world (resetServer)'), and the post-condition routes to restartToApplySettings. It stops short of stating the obvious trigger (user asks to modify an existing server) or any auth/permission prerequisites, so not quite a 5.

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