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

The description meaningfully supplements the annotations: beyond readOnlyHint and idempotentHint, it discloses that the tool does not access the checkout and does not execute the command. This is valuable context for an agent deciding whether the operation is safe and side-effect-free.

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?

A single dense sentence covers the core purpose, scope, and key safety behavior. It is front-loaded with the main action and resource, and no words are 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?

The description is sufficient for a low-complexity, read-only planning tool: it states what is planned, what is returned, and the safety boundary. The lack of an output schema is mitigated by the explicit statement that a safe local DiffCI command is returned.

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 100%, so the schema fully documents all three parameters. The description adds no parameter-specific detail beyond the general context of planning validation actions, but it does not need to compensate for a documentation gap.

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 action ('Plan') and a clear resource (change-aware CI validation, affected-test selection, test impact analysis, GitHub Actions workflow checks), and clarifies that it returns a command rather than executing work. It does not explicitly contrast with the sibling tools, but the purpose is specific enough to avoid confusion.

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 description implies when to use this tool: when you need to plan or validate CI changes locally and get a safe command without checkout access or execution. However, it does not explicitly mention alternatives or state when not to use it, so usage guidance is only implied rather than explicit.

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