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

Annotations already flag destructiveHint=true and readOnlyHint=false, so the mutation risk is known; the description adds genuinely new context by promising that unlisted element settings are preserved, implying partial-update semantics. It does not explain what the destructive flag actually means here (overwriting existing values, irreversibility) or what happens when an animation/projectile ID is cleared.

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 compact sentences, front-loaded with the capability list and ending with the preservation guarantee and the prerequisite lookup. The phrasing 'or their animations' and 'obstacle projectile damage eligibility' is slightly loose but nothing is redundant.

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 mutation with a nested eight-field payload, no output schema and no parameter documentation, the description is only partly sufficient: it omits the projectile_2_id and shoot_1_animation_id roles, whether null means 'clear', and whether referenced IDs must be existing elements. It covers enough to attempt the call but not enough to be confident.

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 coverage is 0% and the nested 'updates' object has eight undocumented properties, so the description must carry the meaning. It credibly maps its phrases to can_take_damage, can_shoot/can_shoot_2, can_move_fast, and the animation-ID fields, which is substantial compensation given the schema is silent.

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 names the concrete settings being changed (NPC/boss damage eligibility, projectile damage, shooting and fast-movement abilities and their animations), which tells the agent far more than the generic name 'update_element'. It stops short of differentiating this 'element' resource from the many sibling update_* tools, but the field list is specific enough to identify the operation.

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 one useful routing hint: element IDs and current settings come from get_game, which points the agent at the correct read tool first. However, there is no statement of when this tool is the right choice versus alternatives, and no preconditions (permissions, whether the element must already exist) are given.

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