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

With no annotations provided, the description carries the full behavioral burden. It discloses that the default path serves from cache with zero Meta API calls, that refresh:true triggers a live re-sync, and that Development-mode apps will appear but Meta refuses to promote them (3858107). This is strong behavioral disclosure, though it doesn't cover error/return edge cases.

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 with no filler: purpose and output usage first, then cache/refresh behavior, then a critical caveat. Every sentence earns its place 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?

For a simple two-parameter list tool with no output schema, the description is nearly complete: it names required context, explains the cache behavior, and warns about the Live-mode requirement. It doesn't fully describe the return shape or pagination, but the expected output is strongly implied by the stated use case.

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 both parameters are already documented. The description reinforces the refresh behavior and explains what the output should be used for, but it doesn't add substantial new parameter-level meaning beyond the schema, so the baseline 3 is appropriate.

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 starts with a specific verb and resource: 'List the apps an ad account can promote.' It immediately states the agent-facing purpose—picking application_id and object_store_url for OUTCOME_APP_PROMOTION campaigns/ad sets—which clearly distinguishes it from sibling list tools.

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 clear context for when to use the tool: when preparing App promotion campaigns/ad sets and needing application_id plus object_store_url. It also explains the cache-vs-refresh decision. It doesn't name explicit alternatives or when-not-to-use cases, but no sibling is a close substitute, so the guidance is sufficient.

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