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

Annotations already declare destructiveHint=true and idempotentHint=true; the description adds the crucial context of what the destructive effect actually touches, namely that the currently active plan is deactivated. It does not cover permission requirements or failure behavior for an invalid planId.

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?

One short sentence, front-loaded with the action and the side effect bracketed immediately after. Nothing wasted.

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 one-parameter mutation with rich annotations and no output schema, the description covers the core effect and its collateral impact. It still leaves gaps on how to obtain a valid planId and what happens on an unknown/archived plan, which matters because there is no output schema to clarify returns.

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 0% for the single required parameter and the description adds nothing about it — no format, no hint that planId comes from stackwell_list_plans, no error semantics. The agent gets only the parameter's name to work with.

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 ('Make a plan the active one'), so the effect is unambiguous. It does not differentiate from nearby siblings such as stackwell_create_plan or stackwell_get_active_plan, so an agent must infer the boundary itself.

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 parenthetical implies when this is relevant (you want a plan to become active, replacing whatever is current), but no explicit when-to-use/when-not statement or named alternative is given. Usage is implied rather than guided.

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