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

Adds substantial behavior beyond the annotations: the call is non-destructive but returns an approval link rather than performing the fix itself, the link must be handed to the user (or account owner), it is single-use and expires in 24 hours, and successful use re-points all of the account's widgets to the new sign-in. Those are exactly the operational facts an agent needs and that readOnlyHint/destructiveHint do not convey. The external platform sign-in described is performed by the human, so it does not meaningfully contradict openWorldHint=false on the tool call itself.

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?

Four short sentences, front-loaded with purpose and trigger, then the user-facing flow and the expiry caveat. Nearly every clause earns its place; only the parenthetical '(or any Instagram, Facebook, TikTok or X account)' is slightly ambiguous in how it qualifies the expired-account precondition.

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?

There is no output schema, and the description supplies the return semantics itself ('the answer is an approval link') along with its one-use, 24-hour lifetime. Combined with the single documented parameter and the non-destructive mutation annotation, an agent has everything needed to call it and act on the result.

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 100% and the single account_id parameter is already documented as 'the id in list_accounts'; the description repeats that same reference without adding format, type, or edge-case guidance (e.g. what happens if the id is not expired). Baseline 3 is appropriate when the schema carries the load.

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 concrete verb and resource — 'renews an account' — plus the exact entry condition ('that list_accounts shows as expired') and the return value ('the answer is an approval link'). The renewal-vs-initial-connection distinction from the sibling connect_account is implied by 'renews' but never named explicitly, which keeps it just short of a 5.

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 triggering context: use it for accounts list_accounts marks as expired, and notes it also works for 'any Instagram, Facebook, TikTok or X account'. It also spells out the downstream human step (open link, sign in, click Allow). It never states when NOT to use it — most notably it does not route the agent to connect_account for a first-time connection.

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