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

Goes well beyond the annotations (readOnlyHint=false, destructiveHint=false) by explaining what actually happens to state: switching on reads preset columns live, switching off hides them, but a column a user has since edited is retained because it has become the workspace's own column. That partial-reversibility detail is exactly the kind of non-obvious behavior an agent cannot infer from structured fields, and it is consistent with destructiveHint=false.

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?

Front-loads the action in the first sentence, then layers prerequisite, behavioral consequence, and permission in a logical order. The long parenthetical about user-edited columns is dense but earns its place; total length is appropriate for a mutation tool with non-trivial side effects.

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?

With an output schema present, the description needn't explain return values, and it covers the essentials an agent needs: id source, authorization requirement, and the effect of each toggle state. It does not address multi-workspace ambiguity or idempotency retries, but the schema handles both explicitly, so the remaining gap is minor.

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 100%, so pack_id, active, workspace_id, conversation_id, idempotency_key and workspace_scope are all documented in the schema itself. The description adds only mild semantic color for `active` ('reads its preset columns live from then on') and repeats the schema's own pointer to well_list_packs for pack ids, so baseline 3 applies.

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 with scope: 'Switch one pack on or off for the workspace.' It also names the sibling that supplies the pack id (well_list_packs), so an agent can distinguish this write tool from the read/list tool without opening either 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 a clear workflow prerequisite ('Use well_list_packs first ... and show the member what it adds') and an authorization gate ('Only a workspace owner or admin may switch a pack on or off'). It stops short of explicit when-not-to-use or a named alternative for other pack operations, so it lands at 4 rather than 5.

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