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

Annotations already disclose the write profile (readOnly=false, destructive=false, idempotent=false). The description adds the real permission nuance that name/CAS are editable only for the user's own materials, which is useful. However, it never says whether constituent/family updates replace or merge existing values, and non-idempotent repeats are unaddressed.

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 front-loaded sentence with the usage trigger first and the field enumeration after; no filler or preamble. The long field list is dense but each item is informative.

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 16-parameter mutation tool with no output schema and very low schema description coverage, the definition is only partially complete. It leaves merge/replace behavior, tier/natural/dropsPerGram handling, and confirmation requirements unexplained, though the field list and permission note cover the essentials.

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 only 13%, so the description carries weight, and it does name most fields (odour, families, note, impact, blotter hours, shelf life, synonyms, flash point, constituents, name, CAS). But it adds little beyond the schema property names and omits tier, natural, dropsPerGram, and any value/format semantics; the 'notes' vs 'note' distinction is ambiguous.

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+resource ('change a material on their bench') and enumerates the mutable fields, so the agent knows exactly what can be edited. It does not explicitly contrast itself with siblings like get_material or search_materials, but the write framing is unmistakable.

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?

The 'Use this when the user wants to change a material' clause gives a clear triggering condition, and the closing clause constrains name/CAS edits to the user's own materials. No explicit when-not or named alternatives, so it stops short of the top score.

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