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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent write, and the description adds auth behavior (sign-in required, the app will prompt to connect an account) plus the post-save lifecycle (reopenable, comparable against current prices, eligible for price alerts). It does not say what happens when the same stack is saved twice, which matters because idempotentHint=false — a minor but real gap.

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 core action and accepted inputs are front-loaded, followed by the follow-up workflow, the auth caveat, and finally the gating rule. Most sentences carry weight, though the account/auth sentences could be tightened slightly without losing meaning.

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 nested-object write tool with an output schema, the description covers everything needed to invoke it correctly: which inputs to pass and in what order of preference, naming guidance, auth preconditions, the recommended downstream call, and a usage gate. Return values are handled by the output schema, so their absence from the description is appropriate.

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 baseline is 3, but the description adds genuine precedence semantics not encoded in the schema: share_url is preferred and plan is the fallback when no share_url exists, and plan is defined as 'plan_stack arguments'. It also illustrates the name parameter with a concrete example.

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 (save) and resource (a recommended stack or app audit) and names the destination account, making clear it is a persistence operation distinct from generation siblings like recommend_stack, plan_stack and audit_stack. The distinction from update_saved_stack is also implied via the follow-up instruction.

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 an explicit trigger condition ('Only save when the user asks to keep or save a stack'), names the preferred input source (share_url from recommend_stack/plan_stack/audit_stack) with a documented fallback (plan_stack arguments), and prescribes the natural next step (offer update_saved_stack with alerts: true). Alternatives and exclusions are both present.

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