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

No annotations are supplied, so the description carries the behavioral burden. It usefully discloses what is returned (field name, value, column visibility) for a simple read operation, but it does not state that the call is read-only, whether it requires auth, how missing items or empty fields behave, or whether pagination applies.

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 sentences, front-loaded with the purpose and followed by the return description. There is no redundant wording or buried detail; it is appropriately sized for a simple one-parameter getter.

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 low-complexity read tool with no output schema and no annotations, the description covers the essential call behavior and return fields. It leaves out edge-case behavior such as missing items or empty custom fields, but the core information needed to invoke it is present.

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?

The sole parameter is undocumented in the schema (0% coverage), so the description must compensate. It clarifies that the integer id refers to the inventory item rather than a custom field, which is useful, but it does not add format, existence, or error semantics beyond the parameter name.

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 and resource — gets custom field values for a given inventory item — and adds the return shape (name, value, column flag), so the agent can tell it apart from definition-listing or mutation tools. It does not explicitly name which sibling to use instead, so it stops short of a 5.

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?

No when-to-use guidance or alternatives are stated; the agent must infer that this is the read path for an item's custom-field values. With many sibling tools such as list_custom_fields and find_units_by_custom_field, the lack of routing guidance is a clear gap.

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