audience_create_geo_circle

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

Annotations already declare the write, idempotent, and non-destructive profile, so the bar is lower. The description adds real policy context beyond them: the operation is 'guarded' and an uncertain outcome must not be resent, which is a retry-safety nuance not captured by idempotentHint=true. It is vague, though, about what counts as 'uncertain' and which reconcile tool to use afterwards.

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?

It is a single front-loaded sentence with no filler, which is efficient. However, for an 8-parameter guarded write with zero schema documentation, one sentence is under-specified rather than appropriately sized.

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 six required parameters, no parameter descriptions, and no annotation for the confirmation/idempotency workflow, the definition should explain how confirmation_hash and idempotency_key relate to the guard. An output schema exists, so return values need not be described, but the call prerequisites are effectively undocumented.

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?

All 8 parameters (name, radius, points, geo_segment_type, confirmation_hash, idempotency_key, period_length, times_quantity) have 0% schema description coverage, and the description mentions none of them. Nothing explains radius units, points format, allowed geo_segment_type values, or what confirmation_hash and idempotency_key must contain.

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 gives a specific verb+resource ('geo-circle create') and the name itself distinguishes it from the sibling audience_create_geo_polygon. It stops short of naming or contrasting any sibling explicitly, so the agent must infer the circle-vs-polygon distinction from the tool name rather than the prose.

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?

'Run one guarded geo-circle create' implies a single invocation, but there is no guidance on when to pick this over audience_create_geo_polygon, audience_validate_create, or the prepare/apply/reconcile family. The 'uncertain outcomes are not resent' line hints at a no-retry policy without saying what to do instead.

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