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

Annotations already declare readOnlyHint=false, destructiveHint=true and idempotentHint=false, but the description adds genuinely new behavioral facts: history is append-only, entries can never be edited or removed, and an order caps at 250 entries. That capacity limit and immutability constraint are not recoverable from the annotations or schema.

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 tight sentences with the write semantics front-loaded before the constraints, and no filler. The trailing REST path is mildly redundant implementation detail but small enough not to hurt readability.

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 mutating tool with full annotation coverage and no output schema, the description supplies the key constraints an agent needs before calling it: immutability and the 250-entry ceiling. It does not say what the call returns or whether existing note content matters, leaving a small gap.

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 order_id, note and source_name are already documented in the schema with their constraints (maxLength 1800, default 'API'). The description adds no syntax, formatting, or source_name guidance beyond what the schema provides, 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 ('append an entry') and resource ('an order's history') up front, prefixed with 'WRITE:' so the operation class is unambiguous. It is plainly distinguishable from sibling writes like orderdesk_add_order_item or orderdesk_add_shipment, which target different resources.

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?

Provides explicit when-not guidance: 'do not use it for routine polling,' which steers the agent away from a misuse pattern. However, it never names an alternative tool (e.g., orderdesk_get_order) for reading history, so the routing guidance is incomplete rather than exhaustive.

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