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

Annotations already cover readOnly/idempotent/non-destructive, so the bar is lower; the description adds real context beyond them: buyer name/address excluded, pending orders counted but not priced, and the zero-day caveat tied to first_day..last_day. It stops short of describing pagination or cardinality limits.

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-loads the core scope, then layers date-selection rules, return contents, and exclusions. Information density is high and each sentence carries weight, though the run of clauses about pending value and zero days makes it slightly dense.

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?

No output schema exists, yet the description enumerates the returned fields (orders, units, cancelled, unshipped, value by currency, best SKUs, recent orders with status) and states key limitations. An agent has enough to call it and interpret results correctly.

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 the interaction between day and days ('days=1 is TODAY so far only; for yesterday pass day=...') which the schema states only in fragments. It clarifies precedence between the two parameters rather than merely restating them.

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 ('Orders for one marketplace'), plus scope ('last N days, default 7, max 30') and the calendar basis ('store's own calendar day'). It explicitly names get_profit_summary as the different sibling, so an agent can distinguish it without opening schemas.

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?

Gives concrete selection rules: days=1 for today-so-far, day='yesterday' or a date for a single day, and routes profit questions to get_profit_summary. It lacks guidance versus other order-adjacent siblings like get_returns, but the core when-to-use is clear.

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