get_ads_campaigns

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

With no annotations provided, the description carries the full behavioral burden and does so: it discloses the required advertising scope and active ads account, and explains that a scope/permission error is surfaced to signal the feature is unavailable. It also states the shape of the return value ('compact list with campaign id, name, status, budget and strategy'), which is essential given there is no output 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?

Front-loads purpose, then usage, then the prerequisite gotcha, then the sibling hand-off, then return contents – a sensible priority order. Every sentence adds distinct information with no restatement of the name or schema.

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 read-only listing tool with three fully documented parameters and no output schema, the description supplies everything essential: what it returns, the auth prerequisites, the failure mode, and the next tool to call. Nothing an agent needs to invoke it correctly is missing.

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 limit, offset and status are already fully documented in the schema. The description only gestures at 'which campaigns exist, their status', adding no format, default, or range detail beyond what the schema states. Baseline 3 applies when the schema does the heavy lifting.

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 ('List the seller's Mercado Ads (Product Ads) campaigns') and immediately scopes the content it covers (status, daily budget, bidding strategy). It is clearly distinguishable from the sibling get_ads_campaign_metrics, which is explicitly named as the performance tool rather than the listing tool.

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?

Gives an explicit use case ('Use this for advertising questions: which campaigns exist...'), states the follow-up workflow ('Get campaign ids here, then check performance with get_ads_campaign_metrics'), and flags the exclusion condition (advertising scope or ads account missing). An agent can route to this tool versus its sibling without inference.

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