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

Goes well beyond the annotations: it enumerates the full destructive cascade (inboxes, messages, attachments, owners, tasks, then API keys, OAuth tokens, webhooks, domains, child account), states that the child key returns 401 afterwards, and documents error semantics (409 workspace_not_empty, 409 owner_required, 404 workspace_not_found, 403 permission_denied). This is exactly the extra context the annotations cannot convey.

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?

Dense but well front-loaded: the trigger, auth, and destructiveness come first, then inputs, return shape, and error behavior. It is long for a delete tool and repeats the destructive/annotation-derived signal ('Destructive'), but nearly every sentence carries actionable information.

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 no output schema, the description supplies the return shape ({id, deleted:true, inboxes_deleted}) and a comprehensive error matrix. For a cascading destructive operation, an agent has everything needed to call it correctly and interpret outcomes.

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%, so both parameters are already documented in the schema. The description restates them and adds the cross-parameter rule (delete_inboxes is effectively required on a non-empty workspace, otherwise 409), which is mildly useful but largely duplicates the schema. Baseline 3 is appropriate.

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 (remove/delete) and resource (sub-account, its API key and mail) with clear scope: a parent removing one of its sub-accounts. An agent can readily distinguish this from cooper_delete_inbox, cooper_delete_thread, or cooper_update_workspace.

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 an explicit trigger condition ('when a parent should remove a sub-account') and the prerequisite context (parent-account ownership). It does not name alternative tools or explicit when-not-to-use cases, but the contextual framing is clear.

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