Contacts: Get Contactable Inboxes

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false. The description usefully adds the required auth mechanism (User API key in the api-access-token header) and notes Persian/Arabic-Indic digit handling for inputs, going beyond the structured safety metadata.

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?

The purpose is front-loaded in one clear sentence, followed by compact endpoint and auth lines. The final localization sentence is somewhat generic and not specific to this endpoint, but it is short and relevant to input formatting.

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 simple two-parameter read-only list tool, the description covers purpose, endpoint, auth, and input encoding. It does not describe the shape of the returned inbox list, which is a minor gap given no output schema exists, but the core information an agent needs to call it correctly is present.

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%, so the schema already documents account_id and id, making 3 the baseline. The description adds meaningful input-format context by noting that IDs and numbers may use Persian or Arabic-Indic digits, which directly affects how those parameters should be supplied.

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 (inboxes through which a contact can be reached), and includes the exact HTTP endpoint. It implies a contact-scoped filter, which separates it from gapify_list_inboxes, but it never explicitly names or contrasts with any sibling tool.

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 lets an agent infer that this is used when the reachable inboxes for a specific contact are needed, but it gives no explicit when-to-use guidance, prerequisites, or alternatives such as gapify_list_inboxes or gapify_create_contact_inbox.

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