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

With no annotations, the description carries the behavioral burden. It discloses that this is a linking operation, not an external account creation, and states the key precondition that the account must already be signed in on the phone. It could mention response/return behavior or duplicate-link side effects, but the core behavioral traits are covered.

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 tight sentences, front-loaded with the core action and default platform, followed by the key prerequisite and platform-specific caveat. No filler or redundant detail.

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 5-parameter tool with no output schema, the description plus full schema coverage gives an agent everything needed to call the tool correctly: prerequisite, platform defaults, and required google_email for YouTube. An explicit note about the success/failure response would round it out, but nothing critical 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 the baseline is 3. The description reinforces platform default and google_email requirement, but these are already stated in the schema property descriptions. It adds no new parameter-level meaning beyond the schema.

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 opens with a specific verb and resource: 'Link a posting account for the authenticated user' on TikTok, Instagram, or YouTube. It also disambiguates the tool's name 'create-account' by clarifying it links an already-existing account rather than creating one, distinguishing it from sibling account tools like delete/update/list/get.

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 clear usage context: the platform defaults to tiktok, the account must already be signed in on the phone slot, and YouTube requires google_email. It lacks explicit 'when not to use' or named alternatives, but the prerequisites and platform-specific conditions are enough for an agent to invoke it correctly.

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