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

Annotations only declare the generic mutation profile (readOnly=false, destructive=false, non-idempotent, open-world); the description adds the consequential behavior: it mints both an app and version 1, membership is captured automatically by the prefix rule rather than hand-added, an empty definition is legal but publishing requires a non-empty membership, and publish=true publishes immediately.

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 create action and the sibling exclusion, and nearly every clause carries information. It is dense with parentheticals and nested examples, which slightly taxes scanning, but nothing is filler.

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 nested-object, non-idempotent creation tool with 5 params, the description covers the authoring loop, the validation source (get_app_definition_schema), the publish precondition, and the sibling alternative. Return values are covered by the output schema, so nothing material is missing.

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% so the baseline is 3; the description climbs above it by explaining that slug is the folder prefix that drives membership capture and that publish=true is the common create-then-publish path. Those are consequences of the parameters, not just restatements of their types.

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 ('create a BRAND-NEW app') and immediately scopes it ('mints the app + its version 1'). It explicitly names the sibling it is not (create_app_version) so an agent can route without inspecting schemas.

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 an explicit entry point ('Start here when building a page or an API bundle'), names the prerequisite workflow (get_app_definition_schema, then author under the prefix), and names the alternative tool for adding a version to an existing app. It also flags when the result is publishable vs. a valid empty draft.

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