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

Annotations already indicate this is read-only and idempotent. The description adds useful behavioral context beyond those annotations, including the per-ZIP/per-date granularity and the same-day ordering cutoff in the recipient's local time zone. No return format or edge-case behavior is described, but for a simple availability check this is not a major gap.

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 three short, purposeful sentences. The primary function is front-loaded, followed by the key scoping distinction and the operational cutoff. There is no filler or redundancy.

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 simple read-only availability check with two fully documented parameters, the description is complete. It covers what the tool does, the granularity of availability, and the key same-day rule. The return value is reasonably implied by 'check whether... is available,' and no output schema exists to demand more.

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 the schema already fully documents both parameters and their formats. The description reinforces the semantics ('US ZIP code', 'given date') but does not add new parameter-level meaning beyond the schema; the same-day cutoff is operational context rather than parameter syntax.

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 names a specific action ('check whether florist delivery is available') and a precise resource/scope ('US ZIP code on a given date'). It also explicitly distinguishes itself from arrangement-level questions by stating availability is 'per ZIP and date, not per arrangement,' which separates it 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 gives clear context for when to use the tool: checking delivery availability for a ZIP and date, and it warns that same-day delivery has a cutoff. It provides a when-not signal via 'not per arrangement,' but it does not name explicit alternatives such as 'use search_arrangements for arrangement-specific delivery details.'

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