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

With annotations (readOnlyHint=false, idempotentHint=false, destructiveHint=false), the safety profile is already covered, yet the description adds real value: it explains that existing stacks are loaded as drafts then updated and applied, and that a new target_stack name creates a single-addon stack. That dual execution path is genuinely useful behavioral context not present in 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?

Two front-loaded sentences with no filler. The core purpose leads, and the behavioral clarification follows immediately; every clause earns its place.

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 non-idempotent mutation tool with no output schema, the description plus annotations and full schema coverage give the agent enough to invoke it correctly. It could be slightly stronger by noting the list_available_charts prerequisite and the post-apply result, but it is largely complete.

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 100%, so the schema already documents every parameter in detail. The description adds the existing-vs-new-name semantics for target_stack, but otherwise just restates required parameters and notably omits cluster_id (also required) and values_override. Baseline 3 is appropriate when the schema carries the detail.

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 ('Install'), resource ('addon from the org chart catalog'), and destination ('into a target stack'), which cleanly distinguishes it from draft-oriented siblings like add_addon_to_stack_profile_draft. The agent knows exactly what operation it performs without opening the 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?

The word 'known' implies the addon must already exist in the catalog, and the schema hints at verify-with-list_available_charts, but the description never names that prerequisite or any alternative path. It gives implied usage context but no explicit when-to-use or when-not-to-use guidance versus rollback_addon, sync_addon, or profile-draft siblings.

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