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

Annotations already declare destructiveHint=true and idempotentHint=false, so the safety profile is covered. The description adds genuine behavioral context beyond them: "Only what you pass changes" clarifies partial-update semantics, and the account-wide blast radius of a visibility change flags the mutation's scope.

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?

The purpose is front-loaded in the first clause, then the body is densely packed with only parameter semantics and prerequisites. Every sentence carries information, though the long visibility-ladder sentence could be tightened slightly.

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 6-parameter mutation tool with no output schema and destructive annotations, the description covers prerequisites, partial-update semantics, scope of impact, and all field meanings. It stops short of explaining whether settings are account- or inbox-scoped or any confirmation requirement, but the essentials are present.

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 33%, but the description documents every parameter: the visibility ladder with its ordered enum values, online_only_assignment's fallback to eligible agents when nobody is online, courtesy_after_resolve with its window range, and priority tiers 1-10 with round-robin tie-breaking. This more than compensates for the sparse schema.

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 opens with a specific verb+resource ("Change Settings → Assignment") and immediately names the read counterpart get_assignment_settings, so an agent can place it precisely relative to siblings. The field-by-field explanation leaves no ambiguity about what the tool operates on.

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?

It gives an explicit prerequisite ("Read get_assignment_settings first") and warns that a visibility change affects every agent in the account, which is strong context. It lacks an explicit "when not to use" or named alternative besides the read tool, keeping it short of a 5.

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