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

Annotations already indicate readOnlyHint=false and destructiveHint=false, so the agent knows this is a mutating but non-destructive operation. The description adds valuable behavioral context: it verifies effective_status, rejects DISAPPROVED ads, and surfaces parent_paused state. This goes beyond the annotations and helps the agent anticipate validation behavior and potential failure modes.

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 concise sentence that front-loads the primary action ('Update ad status') and then lists key behavioral constraints. Every phrase earns its place, though it could be slightly more structured (e.g., separating the action from the validation rules). Overall, it is efficient and readable.

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?

The tool has an output schema (not shown in detail) and 4 parameters with 0% schema description coverage. The description covers the core behavior and validation rules, but it does not explain the role of current_configured_status, what the output contains, or how parent_paused is surfaced (e.g., in the response or as an error). Given the complexity of the operation and the lack of schema descriptions, the description is adequate but leaves gaps.

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%, so the description must compensate. It mentions 'effective_status', 'DISAPPROVED', and 'parent_paused', which relate to the target_configured_status and current_configured_status parameters, but it does not explicitly map these concepts to the parameters. The description adds some meaning (e.g., that DISAPPROVED is rejected), but the agent still lacks clarity on how current_configured_status is used versus target_configured_status. Baseline 3 is appropriate because the description provides some semantic context but not full parameter-level detail.

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 ('Update') and resource ('ad status'), and adds operational constraints (verify effective_status, reject DISAPPROVED, surface parent_paused). It is clear what the tool does, though it doesn't explicitly differentiate from the sibling overview_update_ad_statuses (plural), which likely updates multiple ads at once. The singular/plural distinction is implied but not stated.

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 usage context: it is for updating a single ad's status and includes validation steps. However, it does not explicitly state when to use this tool versus overview_update_ad_statuses (plural) or overview_update_adset_status, nor does it mention any exclusions or prerequisites. The guidance is implied rather than explicit.

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