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

Goes far past the annotations: discloses the per-project scenario cap (422 on overflow), the isolation guarantee (changes invisible until apply_scenario), and the authorization requirement. It also describes what the returned comparison contains. These are exactly the non-obvious traits an agent needs, and nothing contradicts readOnlyHint=false / destructiveHint=false / idempotentHint=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?

Four tight sentences, each carrying distinct information: identity, limit, isolation model, and authorization. The sandbox constraint is front-loaded so an agent knows the risk profile before considering parameters.

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 no output schema, the description compensates by describing what each call returns in the comparison (differing tasks with old and new dates, both project end dates). Between that, the permissions note, and the capacity limit, an agent can call this correctly with realistic expectations.

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% with only two required params (name, projectId), both already documented in the schema including a naming example. The description adds the conceptual meaning of a project-scoped scenario but no syntax, constraints, or naming rules beyond the schema. 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+resource ('Create a scenario for a project') and then defines the resource itself — a private copy of one project's dates that starts identical to the plan. This distinguishes it clearly from apply_scenario (which commits changes) and from list_scenarios/get_scenario.

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?

Explicitly frames the tool as a what-if sandbox whose changes 'touch nothing until apply_scenario', effectively naming the follow-up tool and the condition for switching to it. Also gates the call with 'Administrator/ProjectManager only'. It doesn't discuss delete_scenario or when to prefer working directly on the plan, but the core when/when-not is present.

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