list_sub_accountsList sub-accounts under a given Canvas account.
List sub-accounts under a given Canvas account.
| Name | Required | Description | Default |
|---|---|---|---|
| account_id | Yes | The parent Canvas account ID |
Changes observed during successful MCP inspections.
v1.18.15Input schema / properties / account_id / anyOfAdded value: +[
+ {
+ "exclusiveMinimum": 0,
+ "maximum": 9007199254740991,
+ "type": "integer"
+ },
+ {
+ "pattern": "^[1-9][0-9]{0,18}$",
+ "type": "string"
+ }
+]Input schema / properties / account_id / typeRemoved value: -"number"v1.18.11Input schema / $schemaPrevious value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"v1.18.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe-read profile is covered. The description adds nothing beyond the purpose, saying nothing about pagination, hierarchy depth (does it recurse into nested sub-accounts?), or the return shape. No contradiction with annotations.
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?
A single front-loaded sentence with zero filler, which is appropriate for a simple list tool. It is efficient but borders on under-specification rather than strategic brevity.
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 low-complexity, single-parameter list tool with no output schema and safety covered by annotations, the description is minimally adequate. It nonetheless omits useful context such as whether sub-accounts are returned recursively or paginated.
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% and the single account_id parameter is fully documented in the schema as 'The parent Canvas account ID.' The description adds no semantic detail beyond the schema, so baseline 3 applies.
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 (List) and resource (sub-accounts) scoped to 'under a given Canvas account,' which distinguishes it from the broader list_accounts. However, it does not name any sibling tool explicitly, so the differentiation is left implicit.
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?
There is no when-to-use guidance, no prerequisites, and no mention of alternatives such as list_accounts or get_account. The agent must infer the appropriate context entirely from the resource name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.