Stock lookup

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds genuinely useful behavior beyond that: which fields come back (quantity, reorder level, shortfall, 90-day units sold), the sort order (most critical first) and the 50-row cap.

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?

Front-loaded with the purpose in the first line, followed by examples and then return/sort details; every sentence carries information. The wrapped example list is slightly long but earns its place by clarifying filter usage.

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 read-only, zero-required-parameter lookup with an output schema and full annotation coverage, nothing an agent needs is missing: it knows the trigger questions, the filter surface, the returned fields and the result ordering/cap.

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 100%, so all three parameters are already documented with examples. The description's example questions loosely illustrate the query filter but add no syntax, matching behavior or empty-string semantics beyond the schema, so the baseline 3 applies.

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 and resource ('Look up product stock levels') and immediately grounds it in concrete example questions. An agent can distinguish this from the sibling lookups (order status, customer balance, overdue orders, KPIs) without opening any 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?

The three example questions map cleanly onto the available filters (free-text search, below-reorder, category), giving clear context for when to call it. It stops short of explicitly naming what to use instead if the user wants order-level or supplier-level data, so a 4 rather than a 5.

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