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

Annotations already flag destructiveHint=true, but the description goes well beyond them: it discloses immediate (non-deferred) deletion, cascading removal of all events, that the receive URL stops working, that there is no coin refund, and that the usage ledger persists. These are exactly the consequences an agent needs before calling a destructive tool.

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, front-loaded with the destructive action and cascade effect, then consequences, then the confirmation contract. No filler or repetition.

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 destructive, output-schema-backed tool, the description covers the effect, side effects, irreversible cost implications, and the confirmation gate. Return values need not be explained since an output schema exists.

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 carries the burden for all three parameters. It explains the non-obvious 'confirm' flag fully (must be true, omitted means no action), but says nothing about api_key or inbox_id, which are only inferable from their names.

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 ('Delete an owned inbox') and scopes the blast radius ('and all its events immediately'). It is easily told apart from create_callback_inbox, list_callback_inboxes and read_callback_events by the destructive verb, though it never names a sibling explicitly.

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 confirmation requirement ('Requires confirm=true after reviewing the effect; omitted confirmation performs no action') is clear invocation guidance. However, it offers no when-to-use vs when-not guidance and no routing toward alternatives such as listing or reading the inbox before deleting it.

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