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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so safety is covered. The description adds value by detailing the exact return fields (connections[] and ad_accounts[] with specific properties), which helps the agent understand what to expect. It doesn't discuss pagination or rate limits, but for a simple list operation, this is sufficient.

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 description is a single, well-structured sentence that front-loads the primary action, then provides specific return details and a practical usage note. There is no fluff; every part adds value.

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?

The description gives a clear picture of the output and how to use it, but fails to explain the sole input parameter, which is a notable gap given the low schema coverage. It also omits any mention of limitations (e.g., pagination, authentication prerequisites). For a simple list tool with one optional param, this is not fully complete.

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?

The only parameter 'auth_account' is entirely unexplained. Schema description coverage is 0%, so the description should compensate by describing its purpose. It is optional, but there is no indication of what it does (e.g., which authentication account to use). The description mentions OAuth logins in the response but does not connect this to the parameter, leaving the agent guessing.

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 clearly states it lists Meta connections and ad accounts, specifying the return structure with details like id (act_XXX), name, currency, timezone, status. This is a specific verb+resource that distinguishes it from other meta_ads list tools by the combination of connections and ad accounts.

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?

It provides context on why to use this tool: to obtain the ad_account_id for use in other tools ('Use the ad_account_id in `account` on the other tools'). This implies it is an entry point, but does not explicitly state when not to use it or name alternative tools like meta_ads_business_list for business-level listings.

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