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

Annotations already flag destructiveHint=true, idempotentHint=true and readOnlyHint=false, and the description adds real context on top: the write OVERWRITES the current number, is logged as a stock adjustment, and the underlying endpoint is PUT /admin/inventory_levels/set.json. It does not discuss permission requirements or what happens to concurrent edits, keeping it below a 5.

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?

One front-loaded sentence leading with the WRITE marker, then the overwrite/adjustment caveat, then the prerequisite pointer, then the endpoint. Zero filler and no repetition of schema details.

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 4-parameter mutation with full schema coverage, destructive/idempotent annotations and no output schema, this covers the essential context: absolute semantics, audit reason, overwrite risk, and read-first workflow. Only permission/auth and concurrency behavior are absent.

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 100%, so the baseline is 3, but the description adds meaning the schema does not: 'exact quantity' plus 'OVERWRITES' clarifies that on_hand is an absolute value rather than a delta, and 'with a reason' signals the optional reason parameter's role in the audit record.

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 (set), the exact resource (physical stock / on_hand of one inventory item at one location), and scope limits (one item, one location, exact quantity with a reason). An agent can immediately distinguish it from the read-only sibling sapo_list_inventory_levels.

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?

Explicitly directs the agent to read the level first via sapo_list_inventory_levels, which is a concrete prerequisite step naming an alternative tool. It lacks an explicit when-not-to-use statement (e.g. use a delta/adjustment endpoint for increments), so it falls just short of a 5.

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