Reddit performance

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

Beyond the readOnly/destructive annotations, it discloses data lag up to 6 hours, account timezone default range, account currency, definition of conversions, return components (rows, totals, insights[] with zero-conversion spenders/rejected ads/empty windows), and compact behavior. This is substantial behavioral context not present in structured fields.

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 dense but every sentence adds operational value: metrics first, then return structure, then parameter semantics, then lag/format caveats. Lists are compact and no filler is present.

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 the output schema exists and the description already covers metrics, levels, breakdowns, dates, lag, currency, and compact mode, an agent has what it needs to select parameters and interpret results. The only small omission is ad_account_id resolution, but the overall coverage is excellent.

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 carries the burden; it compensates well by listing level enum values, breakdown dimensions, date format/default, and compact=true behavior. The only minor gap is that ad_account_id is not explicitly described (e.g., how it is resolved when empty), though the parameter name and defaults make it mostly self-explanatory.

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 opens with a specific verb-resource pairing ('Reddit Ads performance') and enumerates concrete metrics (spend, impressions, clicks, CTR, CPC, conversions, CPA, ROAS) and return structure. It clearly identifies this as the aggregate performance tool across levels/breakdowns, distinguishing it from sibling list/entity tools like get_reddit_campaigns or run_reddit_report.

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 gives clear context for use: choose a level, optional breakdown, date range, and compact mode, with defaults and formatting specified. It does not explicitly name alternative tools or state when not to use it, but the description is enough for an agent to recognize the intended reporting use case.

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