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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered and the bar is lower. The description adds scoping context (per-session, orders originating from FIXSIM) and the pairing with fixsim_send_order, but says nothing about paging behavior, ordering beyond the schema's 'newest first', or result shape.

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?

A single tight sentence that front-loads the resource being listed and appends the single-order shortcut. Every clause carries information; nothing is padding.

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, session-scoped listing tool with no output schema and annotations covering safety, the description supplies the scope, the provenance (fixsim_send_order) and the clOrdId shortcut. The main residual gap is that the required session/instance identifiers are never characterized, but an agent has enough to call it 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 only 20% (limit is the sole documented property). The description does compensate for the undocumented clOrdId by explaining it narrows the call to a single order, which is real value the schema lacks. However, the required session and instance parameters, plus apiKey, are left unexplained in both places.

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?

The description names a specific resource (orders sent OUT) and ties it to the originating sibling fixsim_send_order, so an agent can separate it from fixsim_list_orders_in and fixsim_get_order_in. The listing verb itself is only implicit in the noun phrase 'Orders FIXSIM sent OUT', which keeps it just short of a 5.

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?

'Pass clOrdId to fetch one' gives one concrete retrieval mode and the parenthetical names the creating tool, implying this is the read-back side of fixsim_send_order. It never states when to prefer this over fixsim_list_orders_in or fixsim_act_on_orders, so guidance stays implied rather than explicit.

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