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

With no annotations, the description carries the full burden. It usefully discloses the auth/session requirement, which is real behavioral context, but says nothing about duplicate-ID behavior, idempotency, or what a successful registration returns.

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 front-loaded sentence with the verb first and the prerequisite in parentheses. No filler, though the parenthetical could be expanded into a usable precondition statement.

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 mutation tool with no annotations, no output schema, and thin parameter coverage, the description leaves too much unstated: conflict handling, whether the operation is reversible, and what the caller gets back. The auth prerequisite alone is not enough.

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 only 40% across 5 parameters, so the description needs to compensate and does not — bundle_id, bundle_display_name, and bundle_platform are neither explained nor exemplified. Only developer_team_id and notification_message carry schema descriptions.

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: 'Register a new bundle ID on developer.apple.com'. This is clearly distinguishable from list_bundle_ids, get_bundle_id, and delete_bundle_id, though it does not explicitly distinguish itself from the sibling create_app_bundle.

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 gives one concrete precondition: a Developer Identifiers session obtained from start_browser_auth. It does not say when to prefer this over create_app_bundle, nor what to do if the bundle ID already exists.

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