Extend a valid long-lived Meta user access token via token exchange using META_APP_ID and META_APP_SECRET to keep API access active.
Extend a valid long-lived user access token through Meta's documented token exchange flow. Requires META_APP_ID and META_APP_SECRET.
| Name | Required | Description | Default |
|---|---|---|---|
| long_lived_token | Yes | Long-lived access token to refresh |
Changes observed during successful MCP inspections.
v1.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It does add real value by naming the required environment credentials and implying the call hits Meta's documented exchange flow, but it omits failure modes (expired/revoked token, minimum token age), whether the old token is invalidated, and what the resulting token's lifetime is.
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 sentences, front-loaded with the action and followed immediately by the hard prerequisite. No filler, no restatement of the tool name.
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 single-parameter, low-complexity tool with no output schema and no annotations, the description covers the action and credentials but leaves the return value (new token, expiry) and the exchange_token overlap unexplained, which are the two things an agent would most need.
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?
One parameter with 100% schema description coverage ('Long-lived access token to refresh'), so the schema already carries the semantics and the baseline is 3. The description adds no format, source, or validity constraints for the token itself.
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: extend a valid long-lived user access token via Meta's token exchange flow. That is clearly distinct from most siblings, but the sibling set contains exchange_token and debug_token, and the phrase 'token exchange flow' blurs the line with exchange_token without explaining how this differs.
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 a precondition (token must be valid, i.e. not expired) and the config prerequisites META_APP_ID/META_APP_SECRET, which is genuinely useful context. It does not, however, say when to choose this over exchange_token or debug_token, nor what to do when refresh is not possible.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.