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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavior: default working dilution in DPG (or neat) when no strength is given, and that unmatched names return suggestions. It does not address the non-idempotent hint, e.g. whether re-adding the same material duplicates it.

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?

Four sentences, front-loaded with the usage trigger and then progressive detail on formats and defaults. Dense but nearly every clause carries operational information; only the bulk-list sentence runs slightly long.

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 multi-mode, nested-object tool with no output schema and low schema description coverage, the description covers triggers, input variants, defaults, and a partial return behavior. Remaining gaps (duplicate handling, exact return shape, lowStockGrams) are modest rather than blocking.

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?

With only 33% schema description coverage, the description compensates by naming the real-world meaning of most fields (bottle strength, solvent, stock in grams, price per gram, supplier, lot, material by name or CAS) and explaining newMaterial's purpose. The text/file input modes are also spelled out (one material per line, or a table whose header row names columns). It omits lowStockGrams and never maps its vocabulary onto actual property names.

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 and resource (adding catalog or user-created materials to the shelf) and enumerates the per-item attributes it accepts. It is clearly distinguishable from siblings like list_shelf, update_bottle, or search_materials without opening any schema.

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?

"Use this when the user says they have bought or own materials and wants them on their shelf" gives a concrete trigger condition, and the newMaterial clause implicitly routes uncatalogued items. It never names an alternative tool (e.g. search_materials, list_shelf, update_bottle), so the contrast is implied rather than stated.

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