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

Annotations already declare readOnly, idempotent and non-destructive, and the description reinforces them rather than contradicting: changes in the scenario 'touch nothing until apply_scenario'. It adds genuinely new behavioral context by describing the response content (differing tasks, old and new dates, both project end dates) and the role requirement.

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-loaded with the comparison purpose, but the phrase 'the plan as it stands now' appears twice with near-identical wording, so not every sentence earns its place. The access restriction is buried at the end rather than signaled up front.

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 single-parameter read tool with no output schema, the description covers purpose, side-effect profile, permissions and what the answer contains. An agent could call it correctly; only the source of a valid scenario id and any behavior for a stale/applied scenario are left implicit.

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?

Only one parameter and schema coverage is 100%, so the 'Scenario id' description already carries the meaning. The body text only implies the id selects a single scenario, adding nothing about format or how to obtain a valid id (e.g. via list_scenarios). Baseline 3 applies when the schema does the work.

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?

Names a specific verb and resource ('Compare one scenario with the plan as it stands now') and defines what a scenario is (a private copy of one project's dates). The mention of apply_scenario as the commit step distinguishes this read/compare operation from the mutation siblings without the agent needing to open another 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 operating context: this is the non-destructive preview, nothing changes until apply_scenario, and it is restricted to Administrator/ProjectManager. It does not explicitly say when to prefer it over list_scenarios or create_scenario, so it falls short of a full when/when-not treatment.

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