Get channel planning reach

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the scope (Reddit-wide) and output concept (reach curve, impressions vs reach), which is useful given no output schema, but omits auth needs, rate limits, and output details.

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?

A single front-loaded sentence with no wasted words. It states the purpose immediately and is appropriately sized for the information it currently provides.

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 tool with five parameters, zero schema description coverage, and no output schema, the description is too thin. It gives a high-level output concept but omits parameter explanations, usage guidance, and return details that an agent would need for confident invocation.

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% and the description mentions none of the five parameters (duration_days, geolocation, gender, min_age, max_age). It does not compensate for the schema gap or add any meaning beyond the raw enum and type definitions.

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 (Get) and resource (Reddit-wide reach curve) with the output form (impressions vs reach) and purpose (media planning). It is clear, but does not distinguish itself from similar planning tools like reddit_ads_estimate_audience or reddit_ads_suggest_bid.

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 phrase 'for media planning' implies usage context, but there is no explicit when-to-use, when-not-to-use, or alternative selection guidance. An agent would need to infer that this is for planning reach rather than audience estimation or bid suggestions.

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