last_order

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

No annotations are supplied, so the description carries the full behavioral burden. It does disclose a genuine trait beyond the schema — the authentication requirement — but says nothing about behavior when no prior order exists, whether cancelled orders count as 'last,' or any rate/permission constraints.

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?

Two short sentences, resource first and prerequisite second, with zero filler. Nothing wasteful for the amount of content present.

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?

An output schema exists, so return shape need not be described, and login is covered. However, the unexplained 'full' flag leaves a real gap for a tool whose only knob is that flag.

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 0% and the single parameter 'full' (boolean, default false) is never explained. The agent cannot tell whether 'full' expands line items, address, payment info, or something else, which materially affects the response and possibly cost.

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 resource with a narrowing qualifier: 'Your most recently placed order,' which implies a single-record fetch as opposed to the list returned by the sibling my_orders. It does not name order_detail or my_orders explicitly, so the differentiation is implicit rather than stated.

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 prerequisite 'Requires login' is a useful usage condition, but there is no guidance on when to pick this over my_orders, order_detail, or order_invoice, which all deal with orders. The agent must infer the choice from the word 'last.'

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