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

The description states 'Read-only', which matches the annotation readOnlyHint=true, and adds behavioral detail 'Includes creative preview info' beyond the annotation. No contradiction.

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?

The description is a single sentence that efficiently conveys the core purpose and a key feature (creative preview info). No extraneous content.

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?

Given 3 unannotated parameters and no output schema, the description is somewhat incomplete. It does not mention response format, pagination, or detailed parameter semantics, but adequately covers the primary 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?

With 0% schema description coverage, the description must explain parameters. It implicitly explains 'adset_id' via 'inside one ad set', but does not explain 'limit' (pagination) or 'meta_account_id' (account identifier). Only partial compensation.

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 clearly states the verb 'List ads' and specifies the scope 'across the account or inside one ad set', distinguishing it from siblings that list other entities (e.g., list_adsets, list_campaigns). It also mentions 'Includes creative preview info', adding specificity.

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 implies when to use (for ads across account or in one ad set), but does not explicitly state when not to use or name alternatives. The guidance is present but minimal.

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