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

Goes well beyond annotations by disclosing that the target is switched on if inactive, that other active accounts stay active, that the previous primary is switched off to make room when the plan limit would be exceeded (and stays connected), and that otherwise it fails with account_limit. Also clarifies that nothing changes on the ad platform, so no proposal is created.

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-loaded with a WRITE marker and cost line, then behavior, use-when, and not-for. Dense but every section carries distinct information; slightly long but no clearly wasted sentence.

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?

Despite no output schema, the description covers the side effects, the plan-limit failure mode (account_limit), and the absence of platform-side changes. An agent has everything needed to invoke it correctly and interpret the outcome.

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 coverage is 75%; account_id and idempotency_key/raw_data are documented in the schema itself. The description reinforces that the account must be known to Adako but adds no new syntax or format detail beyond what the schema provides, fitting the baseline 3 for adequate-but-not-additive parameter guidance.

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+resource ('Makes one account the primary account for its platform') and clarifies its downstream effect ('the one later tools use when no account id is passed'). This distinguishes it from all sibling account-management tools.

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?

Includes an explicit 'Use when' (user says 'use account X from now on', or account_ambiguous/not_connected after confirmation) and an explicit 'Not for' (manager accounts, which hold no campaigns), plus a prerequisite (account must be known to Adako, see list_connected_accounts).

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