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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, so safety is covered. The description adds genuinely new behavioral context: it returns a single page, uses keyset paging, and that the next_cursor must be passed back as start_cursor — the kind of information the annotations cannot express.

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 short, front-loaded sentences: purpose first, filters second, paging behavior last. No filler and no repetition of annotation-provided facts.

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 no output schema, the description usefully states the shape of the result (quantity per location, one page) and how to page, and all parameters are schema-documented. It could go slightly further on pagination termination or result ordering, but nothing essential is missing for correct invocation.

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 six parameters are already documented, including sort fields, per_page bounds, and cursor semantics. The description restates the two filter parameters and the cursor round-trip without adding format or default details 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 ('List on-hand inventory of parts per part location') with clarifying scope ('quantity by location') and the underlying endpoint. This clearly separates it from sibling list tools such as fleetio_list_parts, which enumerate part definitions rather than stock 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?

It says what can be filtered ('Filter by part or part location'), which implies usage, but never states when to pick this tool over fleetio_list_parts or fleetio_get_part, nor any prerequisites for part_id/part_location_id. Usage is inferable rather than explicit.

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