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

Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false), so the safety burden is largely covered. The description adds some behavioral context by noting stock changes flow 'through the stock ledger' and that shelf/default status can be toggled. It does not disclose how unspecified fields behave on a partial update or any permission requirements, so it adds only moderate value.

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?

It is a single front-loaded sentence opening with the usage trigger, and each clause maps to a real parameter or action, so little is wasted. The density of the enumeration makes it harder to scan than a structured list, but it is appropriately sized for a 14-parameter tool.

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 complex tool with 14 parameters, zero required, low schema coverage and no output schema, the description covers what can be changed but omits how partial updates behave (whether omitted fields are left unchanged) and how the many optional parameters interact. The annotations carry the safety profile, but the operational semantics remain thin.

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 low (29%) with 14 parameters, so the description is expected to compensate. It does map most parameters to user intents (price per gram, supplier, lot, low-stock warning, strength, solvent, notes, shelf, default), but adds little meaning beyond the field names and never clarifies ambiguous ones like the dual meaning of dilutionPct or makeDefault vs onShelf. Marginal value over the schema.

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 gives a specific verb (update) and resource (bottle) and enumerates the concrete fields and actions in scope — stock recording, price per gram, supplier, lot, low-stock warning, strength, solvent, notes, shelf status, preferred bottle. An agent can tell it is a multi-field bottle editor. It does not, however, explicitly contrast itself with siblings like update_material or add_to_shelf, so differentiation is only implied by the bottle-specific field list.

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?

It opens with an explicit trigger: 'Use this when the user wants to record stock... or change...'. This clearly states the context in which the tool applies. It stops short of stating when NOT to use it or naming an alternative tool, so it is a clear-context-but-no-exclusions case.

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