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

Annotations already cover destructiveness and idempotency, but the description adds a crucial operational constraint: deletion only succeeds for accounts with no transactions. This goes beyond the annotations by explaining the failure condition and suggesting fallback actions, which is valuable context not captured elsewhere.

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?

Three sentences with no redundancy: the core action and condition are first, then the alternative path, then the ID source. Every sentence earns its place, and the most critical information is front-loaded.

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?

The tool is simple (one parameter) and the annotations cover the destructive and idempotent aspects. The description supplies the missing behavioral rule (no transactions) and the sibling alternative. With an output schema present, return values need not be described. Nothing critical is omitted.

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?

The schema covers the single parameter id with 100% coverage and a clear description. The tool description echoes the same ID source ('Account IDs come from list_accounts'), adding minimal new information. Since the schema already documents the parameter, a baseline of 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?

The description provides a specific verb and resource ('deletes an account') plus a critical precondition ('has no transactions'), which clearly distinguishes this tool from other delete_* siblings. It also references the alternative archiving mechanism, making the purpose unmistakable.

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?

Explicitly states when to use this tool versus alternatives: 'An account with history cannot be deleted — archive it with update_account (archived: true) or delete its transactions first.' It also specifies the ID source via list_accounts, giving clear prerequisites and exclusions.

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