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

Annotations declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds operational context by specifying return types (earliest/latest estimate) and warning categories (PO box, hotel, holiday window) with a suggested action, which is valuable beyond annotations.

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 exactly two sentences: the first states the purpose and expected output, the second gives usage guidance. It is front-loaded, efficient, and contains no redundant or filler content.

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?

Given the presence of an output schema and high schema coverage, the description need not explain return structures in detail. It covers the main use case, key output types, and common warnings. It could be slightly more explicit about negative results (e.g., infeasible delivery), but overall it is adequate.

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%, with each parameter thoroughly documented (e.g., city for warnings only, locale localizes messages). The tool description only paraphrases these (e.g., 'by a date' for date_needed) without adding new semantic depth, so it meets the baseline but does not exceed it.

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 explicitly states the tool checks delivery feasibility to a country with optional city, date, and gift, returning estimates and warnings. This is a specific verb+resource that clearly distinguishes it from siblings like 'search_gifts' or 'get_order_status'.

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 phrase 'Use it whenever the user has a deadline' provides clear contextual guidance for when to invoke this tool. It does not explicitly mention alternatives or when not to use it, but the deadline trigger is a strong discriminator.

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