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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds genuinely new behavioral facts: results are capped at 500, a truncated flag is returned, and date filters use YYYY-MM-DD. It does not discuss pagination past the cap or auth requirements, so it is not a 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?

Four short sentences, each carrying distinct information: scope, the optional narrowing parameter, date format, and the return cap plus the sourcing of bc_id. The scoping statement is front-loaded and nothing is repeated from the schema or annotations.

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?

With an output schema present, return-value detail is not required, and the description covers the entry point (bc_id source), filtering, and date formatting. A five-param tool with 0% schema coverage could still benefit from stating defaults and whether date filters are inclusive, but the description is otherwise complete for correct invocation.

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 0%, so the description must carry the load, and it does: advertiser_id is described as an optional narrowing filter, start_date/end_date as YYYY-MM-DD, limit as capped at 500, and bc_id as coming from list_tiktok_business_centers. It omits the limit default and the empty-string defaults, but that is minor.

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 names a specific verb and resource ('change log — who changed what and when (audit trail)') and scopes it precisely to a Business Center's ad accounts, which separates it from the generic get_change_history and meta_change_history siblings. It stops short of explicitly naming a sibling it is not, so it lands just below the top tier.

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?

It gives clear context: this is a per-Business-Center audit trail, and advertiser_id optionally narrows the result to one account. It also routes the agent to list_tiktok_business_centers for obtaining bc_id, which is real usage guidance. It does not state any when-not-to-use conditions.

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