Add Facebook Account

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

The description adds meaningful behavioral context beyond annotations: it explains that adding an account can change the active identity ('when set_as_active is True (default)') and specifies the required cookie fields. This complements the destructiveHint annotation rather than contradicting it. It does not cover every edge case (e.g., what happens if the account already exists), but it discloses the key behavioral impact.

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 two sentences, front-loaded with the primary purpose, and every sentence carries crucial information. It avoids redundancy and fluff, making it highly efficient for an AI agent to parse quickly.

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?

Given the tool has 6 parameters, a nested object, and an output schema, the description covers the core requirements (cookies, active identity change) without needing to explain return values. It is complete enough for an agent to understand the main use case, though it could mention error conditions or validation behavior for full completeness.

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 schema already provides descriptions for all 6 parameters, but the description adds essential semantics for the cookies parameter by specifying it 'must contain at least c_user and xs' as a logged-in session. It also clarifies the effect of set_as_active on subsequent tool actions. This adds value over the schema's terse descriptions.

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 the tool's action: 'Store a new Facebook identity's cookie set for agent use.' It specifies the resource (Facebook identity cookie set) and scope (new identity), distinguishing it from sibling tools like update_account_cookies or import_account_from_browser. The title 'Add Facebook Account' aligns with this clear purpose.

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?

The description gives solid context for when to use the tool: when you have a logged-in facebook.com session cookie set with at least c_user and xs. It also explains the behavioral consequence ('After adding, all tools act as this identity') but does not explicitly mention alternatives or when not to use it, such as comparing with import_account_from_browser. Thus, clear context but lacking explicit exclusions/alternatives.

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