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

Annotations already declare readOnlyHint=false, destructiveHint=true, and idempotentHint=true, so the write/idempotency profile is covered structurally. The description adds one genuinely new fact beyond structured data, the required write scope, but does not explain what the destructive hint means here (e.g. whether lowering quantity to 0 removes the association).

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?

Two short sentences, zero padding, with the action and target record front-loaded ahead of the permission requirement. Nothing could be trimmed without losing information.

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 two-parameter mutation with full annotations and a complete schema, the definition supplies the essential missing piece (the required scope). Only edge-case behavior, such as what a quantity of 0 does to the association, is left unstated.

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 100% and both parameters ('id' as asset-part association ID, 'quantity' as new quantity with minimum 0) are documented there. The description only mirrors that 'quantity' is the target field, adding no format, range, or edge-case semantics beyond the schema, so the baseline 3 applies.

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 a specific verb (Update), a specific resource (asset-part association), and even the single mutable field (quantity), plus the identifier used to select the record. This separates it well from delete_asset_part or get_asset_part, though it never explicitly names update_infrastructure_asset_part as the near-twin sibling.

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?

It states a real prerequisite (asset_parts:write scope) and implicitly frames usage as 'changed the quantity of an existing association,' but never says when to choose this over create_asset_part, delete_asset_part, or bulk_update. No exclusions or alternative routing are given.

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