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

Annotations already declare readOnlyHint=true, so safety is covered, but the description still adds genuine behavioral value: it names the returned fields `available` and `plannable` and explains that plannable can exceed available when shortage is allowed. That semantic distinction is not obtainable from annotations or schema. It stops short of a 5 by omitting any rate-limit or partial-result behavior.

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 short sentences, front-loaded with the core purpose, then return semantics, then the prerequisite pointer and endpoint. Every sentence carries distinct information with no filler.

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?

With no output schema, the description usefully explains the two return fields, and it covers the location-id prerequisite. What it lacks is any routing against the sibling availability/calendar tool and pagination or batch-size context (e.g. the 50-product cap already in schema).

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%, including the nuanced note that `from`/`till` must be expressed in local time written as UTC. The description adds no parameter-level meaning beyond that, so the baseline 3 for full schema coverage applies.

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?

States a specific verb+resource+scope: 'How many units of one or more products can be booked for an exact period at a location.' An agent knows exactly what it computes. However it does not name the sibling it differs from (booqable_get_availability_calendar), so sibling differentiation is absent, keeping it short of a 5.

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?

Provides a useful prerequisite pointer ('Get location ids from booqable_list_locations'), which is real usage context. But there is no when-to-use/when-not guidance and no comparison to the closely related booqable_get_availability_calendar, leaving the agent to infer which availability tool fits the situation.

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