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

Annotations already flag destructiveHint=true and idempotentHint=false; the description adds genuinely new behavioral facts: the required API-key scope `feedback:bugs:write`, that emails resolve case-insensitively against workspace members, and the 400 on dual-assignment. Missing is what happens to the previous assignee (notification/replacement) and the success response, but the disclosure goes well past the annotations.

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?

Three compact sentences, verb-and-resource first, then the parameter rule, then the auth scope — no filler and nothing that could be cut without losing information.

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 single-purpose mutation with no output schema and annotations already covering safety, the description supplies the remaining decision-critical details: mutual exclusivity, unassign default, email resolution, and required scope.

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?

The critical cross-field constraint (exactly one of two assignee params, neither means unassign) cannot be expressed in this flat schema and is stated clearly, along with email resolution rules. shortId is left unexplained, but schema coverage at 60% handles account and workspace.

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?

Opens with a specific verb pair (assign/unassign) and resource (bug), and the semantics of the two directions are stated immediately. An agent can distinguish this from fr_set_bug_status or fr_set_bug_visibility without reading any schema.

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 explicit call-shape rules: supply exactly one of assigneeEmail or assigneeId, both yields 400, and neither unassigns. It does not contrast with sibling tools (e.g. status vs. assignee vs. visibility changes), so it stops short of full when/when-not guidance.

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