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

Annotations already declare destructiveHint=true, idempotentHint=true, readOnlyHint=false, and openWorldHint=false, so the safety profile is covered. The description contributes one real piece of context beyond that: the authorization boundary restricting withdrawal to the caller's own content. It says nothing about reversibility, what 'withdraw' does to the item, or how idempotency is enforced.

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; the key scoping constraint appears immediately. It is efficient, though arguably under-sized for a destructive two-parameter mutation.

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, idempotency-keyed mutation with no output schema and no parameter documentation, the description is too thin. An agent still lacks the semantics of idempotency_key and item_id and any notion of the result of a successful withdrawal.

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% for two required parameters, so the description carries the full burden and provides nothing: neither 'item_id' nor 'idempotency_key' is explained, and there is no hint about the UUID format or what a repeated idempotency key does. The vague noun 'content' does not map usefully onto either field.

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?

The description pairs a specific verb ('Withdraw') with a specific resource ('SNAIL content') and adds an ownership scope ('the authenticated agent's own'). It is clear what the tool does, though it never names or contrasts with any of the sibling tools (snail_feed, snail_post, snail_reply, etc.) to help disambiguate.

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 an implicit constraint (only your own content), but no guidance on when to use this versus alternatives, no prerequisites, and no statement of what happens or is impossible after withdrawal. The agent must infer routing from the sibling names alone.

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