list_materials

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

With no annotations, the description carries the full burden, yet it says nothing about whether the call is read-only, whether search is a substring or prefix match, case sensitivity, result limits, or what happens when the library is not loaded. The only behavioral hint is that returned names must match exactly, which is about downstream use rather than this call.

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?

A single compact sentence with no filler, and the useful constraint (names are the exact strings passed to downstream tools) is front-loaded. The phrasing is slightly fragmented, but nothing is wasted.

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?

An output schema exists, so return format needn't be explained, and the schema covers the instance selector. However, for a lookup tool the one thing an agent most needs — how 'search' matches and whether an empty search returns everything — is not addressed anywhere.

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 50%: 'instance' is documented in the schema, but 'search' has no schema description, and the description only supplies example values ('steel', 'alum') without stating matching semantics. That partially compensates for the gap but leaves the key parameter's behavior underspecified.

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 resource precisely ('Material names in Inventor's libraries') and distinguishes it from mutating siblings by pointing at set_material/properties/create_part as consumers. It never states an explicit verb like 'list' or 'search', but the resource and scope are unambiguous.

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?

Usage is only implied: the examples ('search="steel"') and the pointer to the tools that consume the returned names suggest the lookup-then-set workflow. There is no explicit statement of when to use this versus material_report or content_center, nor any note about prerequisites such as a connected instance.

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