get_meta_hourly_performance

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

No annotations are provided, so the description bears full burden. It discloses the time-zone semantics (audience time zone) and how dimensions are derived (day-of-week client-side, hours from Meta's hourly_stats_aggregated_by_audience_time_zone), which is useful behavioral context. However, it omits the safety profile (read-only?), rate limits, and pagination behavior.

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?

Two dense sentences with no filler. The purpose and use case are front-loaded, followed by metric and derivation details. Slightly long but every clause earns its place for a complex analytical tool.

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?

No output schema exists, so the description correctly enumerates the returned metrics and their sources. It covers the analytical context and data derivation. Lacks explicit mention of the zero-required-parameter behavior (e.g., returns all campaigns if campaign_ids omitted, defaults for date range are in schema). Fairly complete but missing some operational details.

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 the schema already documents all five parameters. The description adds no additional meaning about parameter syntax or defaults beyond what the schema provides. Baseline 3 applies.

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 ('Returns Meta Ads performance broken down by hour-of-day and day-of-week per campaign'), distinguishing it explicitly from the sibling get_meta_campaign_performance, which lacks the dayparting dimension. The granularity (hour 0-23, MONDAY-SUNDAY) 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?

Gives a clear use case ('Use for dayparting / ad-set scheduling analysis') and the analytical goal ('identify when ads perform best and worst'). Does not explicitly name the alternative (get_meta_campaign_performance) or state when not to use this tool, but the intended context is clear.

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