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

With minimal annotations (readOnlyHint=false, non-destructive, non-idempotent), the description carries real weight and delivers: the link expires in one hour, no account is connected until the user finishes the browser flow, and the response contains url plus message_for_user. It doesn't mention auth/permission requirements or re-issuing behavior, so not a full 5.

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 the core action and expiry, and every clause carries information (flow mechanics, Instagram specifics, return values). It is a long run-on sentence with some detail (the Facebook Page fallback) that could be trimmed, but nothing is filler.

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 zero-required-param tool with no output schema, it covers the full lifecycle an agent needs: what it creates, expiry, that side effects are user-gated, how the two optional params change behavior, and what the response returns.

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 already 100%, so the baseline is 3, but the description adds genuine semantics: platform narrows the page to a single network while omitting it lets the user choose, and brand_id routes the resulting connections to a specific brand. That goes beyond the schema's terse property 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?

States a specific verb and resource ('Creates a one-hour link the user opens in a browser to connect social accounts') and immediately scopes it with the networks and the PostWire account. The 'link' family siblings (create_upload_link, get_upgrade_link) are clearly differentiated by the connect-accounts 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?

Gives clear context: use it to generate a page where the user connects one or many networks, and nothing happens until the user completes the flow. It explains the platform/brand_id selection modes but never names an alternative tool or states an exclusion, so it stops short of full when-not guidance.

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