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

Annotations already declare destructiveHint=true, readOnlyHint=false, idempotentHint=false and openWorldHint=true, so the safety profile is covered structurally. The description's 'sensitive write operation; requires confirm=true' largely restates the schema's confirm const and the destructive annotation, adding little new behavioral context (no auth, side effects, or reversibility detail).

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, front-loaded with the action and endpoint, then the constraint. Minimal waste, though the endpoint restatement is somewhat redundant with the name.

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 10-parameter destructive mutation with no output schema, the description covers the crucial confirmation gate and sensitivity flag. It omits the polymorphic 'users' shape and the 'to'/'from' range semantics, but the schema carries part of that load and no output contract needs explaining.

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 60%, so some parameters (confirm, base_url, api_token, account_id, access_token, app_password) are documented in the schema itself. The description reinforces the confirm requirement but says nothing about the undocumented/ambiguous 'users' (array vs number vs string), 'to'/'from', or schedule_id semantics, so it doesn't compensate for the remaining 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 ('Assigns users to a schedule') and pins the exact endpoint GET /schedules/:schedule_id/users/assign. This clearly distinguishes it from siblings like remove_users_from_schedule and assign_user_projects.

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?

The 'Limitations' clause establishes a precondition (requires confirm=true) and flags the operation as sensitive, which implies caution. However, it never says when to prefer this over remove_users_from_schedule or how it relates to other assignment tools, leaving routing guidance implied.

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