search_geo_lookup

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

No annotations exist, so the description carries the behavioral burden. It conveys a read-only search operation and explains what the output is for (targeting IDs), which is useful. However, it does not disclose output shape/format, whether ad_acccount_id is required, or any rate/limit behavior beyond the schema's limit param.

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?

Three sentences with zero fluff: purpose first, then downstream usage, then a concrete chain example. Every sentence carries distinct information and the most important scoping detail (what the tool returns and how to use it) is front-loaded.

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 simple 3-param lookup tool with no output schema and no annotations, the description covers the core workflow end-to-end. The main gaps are the exact response structure and the role of ad_account_id, but the chain example partially bridges the former; nothing critical is missing for a competent agent.

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 covers q and limit (67%), and the description reinforces q's semantics with a concrete example ('California') and shows how results map to targeting.locations.include. However, ad_account_id has no description in either schema or description, and the description does not clarify when it is needed, so the gap is not fully compensated.

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 ('Search DMA and standard region codes') plus its purpose ('advertiser geo targeting'). No sibling tool performs geo lookup, so it is immediately distinguishable from campaign, audience, and ad management tools. The scope and deliverable ('location IDs') are both explicit.

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?

Provides an explicit workflow: search first, then feed returned IDs into campaign targeting.locations.include, with a concrete chain example (search_geo_lookup {q:'California'} -> create_campaign). It doesn't state when-not-to-use or name alternatives, but none exist among siblings, so the positive guidance is sufficient.

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