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

With no annotations provided, the description carries full burden. It states it 'checks' but does not disclose whether the tool is read-only, what constitutes 'recent' (time window), the exact return value, or any side-effects. This leaves significant ambiguity for an AI agent.

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 description is a single sentence of 15 words, front-loaded with the verb 'Check', and contains zero filler. Every word serves a purpose, achieving maximum conciseness.

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 has no output schema, so the description should explain the return value. It only says 'Check whether...' without stating what the tool returns (boolean, order ID, etc.). Additionally, 'recent' is vague. For a simple 1-parameter tool, this lack of completeness forces the agent to guess behavior.

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 baseline is 3. The tool description adds context ('duplicate-shipment guard') but does not add format, constraints, or example values beyond the schema's 'Customer phone number' description. It meets the minimum but does not exceed.

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 clearly states the tool checks if a phone number has a recent order, with a specific use case ('duplicate-shipment guard'). The verb 'check' and resource 'customer phone number' are precise, and it distinguishes itself clearly from sibling tools that create, cancel, or retrieve orders.

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?

No explicit guidance on when to use this tool versus alternatives. The phrase 'duplicate-shipment guard' hints at use before creating an order, but there is no when-to-use, prerequisites, or mention of related tools like create_order. The agent must infer usage context.

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