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

Annotations already declare destructive=true, idempotent=true, and readOnly=false, so the safety profile is covered. The description adds genuinely useful nuance beyond them: cancellation only affects future steps and pending deliveries, while an already-claimed or in-flight delivery may still complete — exactly the residual-risk detail an agent needs before deciding to cancel.

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, zero filler, with the primary effect (cancels future steps and pending deliveries) front-loaded and the caveat immediately after. Nothing needs trimming or reordering.

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 values need not be described, and the annotations plus the in-flight-delivery caveat give a solid behavioral picture for a destructive, idempotent operation. The only meaningful gap is the undocumented routine_id parameter, which leaves the agent guessing at the expected identifier format.

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?

There is a single parameter, routine_id, and schema description coverage is 0%: the schema only carries a regex pattern with no prose explaining that it is a 64-character hex routine identifier or where to obtain one. The description mentions nothing about the parameter, so it fails to compensate for the coverage gap.

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 ('Cancel a server routine') and adds the scope of cancellation: future steps and pending deliveries. It doesn't explicitly contrast with the sibling cancel_server_timer, so an agent must rely on the name alone to pick between the two, but the purpose itself is unambiguous.

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?

Usage is implied by the name and the scope sentence, but there is no explicit when-to-use guidance, no mention of prerequisites such as the routine having to exist or be unclaimed, and no naming of alternatives (e.g., cancel_server_timer). The agent can infer the context but is given nothing to disambiguate siblings.

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