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

No annotations are provided, so the description carries the full behavioral burden and does not meet it. It says nothing about session persistence, whether credentials are stored, rate limiting, how a bad TOTP is surfaced, or what the tool returns on success or failure. For a stateful authentication operation with zero annotation coverage this is a significant disclosure gap.

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?

Two compact sentences with the authentication purpose front-loaded and no filler. The Nova credential import reference is a slightly obscure aside, but it does carry format information, so it earns most of its space.

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 an authentication tool with no annotations and no output schema, the description should say what a successful vs failed login produces and how it relates to downstream calls. Neither is covered, leaving the agent unable to predict return values or prerequisite ordering. The 100% schema coverage offsets this only partially.

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 the baseline is 3 and the schema already explains each field including the TOTP-vs-code distinction. The description adds only a small amount of value by giving the colon-delimited field order used for Nova credential import. It says nothing about the notification_message field or its fallback behavior.

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: authenticate into an Instagram Mobile account using username, password, and TOTP secret. It is unambiguous and no sibling tool overlaps with authentication. It stops short of a 5 only because it does not explicitly frame itself as the prerequisite gate for the other Instagram 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?

There is no guidance on when this must be called relative to direct_inbox, user_feed, send_dm, or the rest of the sibling set. An agent gets no signal that this is a prerequisite step or what to do on a 2FA challenge or failed login. Usage is only implied by the tool name.

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