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

Annotations already mark the tool read-only and idempotent. The description adds useful behavioral context: availability depends on ZIP and date, and same-day delivery has a cutoff in the recipient's time zone. No contradictions with 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?

Three concise sentences, front-loaded with the core purpose, followed by a scope clarification and a practical rule. 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?

The tool is simple with two fully documented parameters, but there is no output schema and the description does not state the return format (e.g., boolean or availability details). For a read-only check, this leaves some ambiguity about the response shape.

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 input schema already fully documents both parameters (zip pattern and date format with local-date semantics). The description adds the same-day cutoff constraint tied to the date and clarifies that availability is not per arrangement, giving extra meaning beyond the schema.

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's function: checking florist delivery availability for a given US ZIP and date. It further distinguishes itself from arrangement-related tasks by noting availability is per ZIP/date, not per arrangement, clearly differentiating from sibling tools like search_arrangements.

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 description states the tool is for checking availability per ZIP and date, explicitly excluding arrangement-specific availability, which signals when not to use it. It also provides the same-day cutoff rule (before 2 PM recipient local time). However, it doesn't name the sibling tool for arrangement-specific checks, so the guidance is implicit rather than explicit.

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