get_audience_reach

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

Annotations already establish the read-only, idempotent, non-destructive, open-world profile, lowering the bar. The description adds domain context by defining the audiencePenetration metric and its formula, plus the 92-day date constraint, though the latter partly duplicates the schema.

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 definition leads with the purpose and keeps to four short sentences. The 'Helps understand what percentage...' sentence is somewhat redundant with the preceding metric definition, but overall it is well front-loaded and low-waste.

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?

With no output schema, the description carries the burden of explaining return values, and it does define the key audiencePenetration metric. It stops short of describing other fields or aggregation/segmentation behavior, leaving a small gap for a reporting tool.

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 all five parameters are already documented in the schema. The description adds no parameter-level syntax or format beyond the date-range note, so the baseline of 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?

The description states a specific verb and resource (shows unique member reach / audience penetration for campaigns) and even names the exact metric returned (audiencePenetration). It does not, however, differentiate itself from siblings like get_audience_demographics or get_analytics, so an agent must infer when reach is the right 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?

Usage is only implied: 'Helps understand what percentage of your target audience you've reached' suggests a reach-measurement context but gives no explicit when-to-use or when-to-prefer-a-sibling guidance. The 92-day constraint is included, which is useful, but no alternatives are named.

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