apple_set_app_info

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

With no annotations, the description carries the full burden. It does disclose useful behavior: 'External action' flags a side effect, and 'Only the fields passed are changed' documents partial-update semantics, plus the non-obvious fact that fields live on two different resources (appInfo vs. editable version). However it says nothing about authentication/permissions required, reversibility, or whether changes go live 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 purpose and the sibling boundary, then a compact enumeration of field placement. No filler sentences, though the second paragraph is a dense run-on.

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?

An output schema exists, so return values need not be described. For a 10-parameter mutation tool with 0% schema coverage and no annotations, the description covers most listing fields but leaves locale (and its pt-BR default) and uses_third_party_content entirely undocumented.

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 0% across 10 parameters, so the description must compensate. It adds real meaning for the category fields (Apple IDs such as MEDICAL, HEALTH_AND_FITNESS) and maps most listing fields to their owning resource, but app_id, locale, and uses_third_party_content are never explained.

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+resource ('Fill in the listing fields') and explicitly carves out scope relative to the sibling apple_update_listing, so an agent can tell the two apart. It is slightly indirect in that the exact fields are only revealed in the following sentence, but the purpose is unambiguous.

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?

It names the alternative tool (apple_update_listing) and defines the boundary: use this for the fields update_listing does not cover. There is no explicit statement of prerequisites or when not to use it, but the routing rule is clear.

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