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

Annotations already cover readOnlyHint=false, idempotentHint=true, and destructiveHint=false. The description adds meaningful behavioral context beyond those annotations: the slug is immutable, renaming breaks nothing, and it returns the updated object. It does not over-explain but provides enough to set expectations for a mutation.

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?

Three sentences, each earning its place: the action, the crucial immutability caveat, the alternative when slug must change, and the return shape. No filler or redundancy, and the most important information is front-loaded.

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 covers the action, consequences, alternatives, and return type explicitly. Since there is no output schema, listing the returned fields is valuable and completes the picture. The annotation set already covers the safety profile, so no missing behavioral disclosure is apparent.

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 baseline is 3. The parameters app, org, and name are already well documented in the schema with examples. The description adds some context about the slug being immutable but does not need to repeat parameter details. It earns the baseline but no higher.

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?

The description states a specific verb and resource ('Change an application's display name') and clearly distinguishes this tool from delete_app + create_app by explaining the slug is immutable. It is immediately clear that this tool is for renaming an app's display name, not for changing the slug or affecting other resources.

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 explicitly says when to use this tool vs the alternative: 'Use delete_app + create_app only if the slug itself must change.' It also reassures that renaming breaks nothing because other tools refer to the app by slug. This gives an agent a clear decision rule.

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