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

No annotations are provided, so the description carries the full behavioral burden. It does disclose the returned fields (price, admin fee, availability count) and that filtering is optional, which is genuinely useful given there is no output schema, but it says nothing about auth requirements, rate limits, data freshness, or pagination.

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?

Two tight sentences with no filler, and the filter semantics are stated compactly. It front-loads return content rather than the action verb, which is slightly unusual but still informative.

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 2-param read tool with no output schema and no annotations, the description covers the payload and filter behavior reasonably. It is missing the default behavior when no filter is supplied (all units?) and any note on data freshness, which matters for an availability listing.

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 coverage is only 50% — the enum for 'type' has no schema description — and the description compensates by naming the two valid enum values ("drive_up", "climate_controlled") and giving a size example ("10x10"). This adds meaning beyond the schema for the undocumented parameter.

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 conveys the resource (available storage units per size/type) and the payload (monthly price, admin fee, unit count), so an agent knows what it will get back. It does not, however, explicitly differentiate itself from the sibling get_facility_info or create_booking_link.

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?

"Optionally filter by size and/or type" tells the agent the filters are optional, which implies the tool can be called unfiltered, but there is no when-to-use/when-not guidance and no routing against the sibling tools. Usage is only implied.

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