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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful behavior: colorants are only searched when explicitly requested ("if asked"), and matching spans aliases and makers, not just literal names.

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 tightly written sentences with no filler. The scope (what is searchable) is front-loaded and the routing purpose follows immediately.

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 5-parameter read-only search with no output schema and 80% schema coverage, the description covers scope, matching keys and the conditional colorant behavior. Return shape and pagination/limit behavior are not described, but with no output schema declared that omission is minor.

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 80%, so the baseline is 3. The description earns above baseline by clarifying that matching extends to aliases and makers (beyond the schema's "Words in the name") and by tying the optional colorant scope to an explicit request, which maps to includeColorants.

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 (Finds) plus the resource (ceramic raw materials) and enumerates the concrete material types (feldspars, clays, frits, fluxes) and matching keys (name, alias, maker). This is clearly a lookup/search tool, distinguishable from the sibling get_material, which retrieves a single material by an already-known name.

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 it to find the exact name the other tools take" gives an explicit entry-point role relative to siblings like get_material, analyze_recipe and match_from_materials. It stops short of naming a when-not case or a specific alternative tool, so it is clear context without full routing rules.

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