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

Annotations already cover read-only/idempotent/non-destructive, so the bar is lower. The description adds genuinely non-obvious behavior beyond the annotations: monetary amounts are returned as bare numbers with no currency embedded, and a follow-up call is needed to interpret them.

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 tight sentences with zero padding; the core purpose is front-loaded and the currency caveat is placed immediately after the content description it modifies.

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 gives the agent the key result shape (location, stock levels) plus the currency interpretation warning, which is what an agent needs to report values correctly. A little more on how missing parts are signaled would complete it.

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 (id) and schema coverage is 100%, with the UUID format and pattern fully documented in the schema. The description adds nothing further about the identifier, 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?

States a specific verb (Get) and resource (part) and enumerates the payload contents (location, stock levels), which distinguishes it from the create/update/delete/list siblings. It does not explicitly name list_parts as the alternative, so it stops short of full sibling routing.

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?

Gives a concrete, actionable usage rule: amounts are bare numbers, so call get_organization_settings for currency_code before stating one. That is real when-to-use guidance involving another tool, though it doesn't say when to prefer this over list_parts.

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