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

Annotations already declare idempotentHint=true, destructiveHint=false and readOnlyHint=false, so the safety profile is largely covered; the description adds the scope of what actually changes. Minor gap: it advertises 'thaw' as an action while the state enum only offers sealed/open/frozen/finished, which an agent must reconcile via unfrozen_at, and it says nothing about permissions or partial-update semantics for the fields object.

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?

Three tight sentences: capability first, sourcing of bag_id second, sibling hand-off last. No filler, and the most load-bearing information (what the tool changes) is front-loaded.

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?

With annotations covering safety and an output schema present, the description supplies the scope and the alternative-tool routing that the structured fields cannot. It is slightly incomplete about the thaw/state reconciliation, but otherwise sufficient for a 3-parameter mutation tool.

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 67% and the nested fields object carries its own per-field descriptions (e.g. grams_remaining, weight_adjustment_g, bag_id 'Never guess one'). The description names a few updatable fields but adds no syntax or meaning beyond the schema, so baseline 3 is appropriate given the schema does the heavy lifting.

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 concrete verb and resource ('Change bag-level facts on one bag of a coffee') and enumerates the actual mutations (open, seal, freeze, thaw, finish, correct roast date/weight/grams left/price). It explicitly distinguishes itself from the sibling update_bean ('For the coffee itself ... use update_bean'), so an agent can route without opening either 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?

Gives explicit routing: bag-level facts go here, coffee-level facts (roaster, origin, roast level, rest window, notes) go to update_bean. It also tells the agent where bag numbers come from ('from the bags[] on list_beans (or current_bag_id)'). When-to-use and the alternative are both present.

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