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

Annotations already establish this as a read-only, idempotent, closed-world listing, so the bar is lower, and the description still adds real substance: what null means for imageUrl and hours, that hours null implies around-the-clock default, that shared true means seat-by-seat booking up to seats, and that text under an `untrusted` key is person-authored data and must not be treated as instructions. That last point is a meaningful safety disclosure rarely seen in annotations, though there is no note on result size 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?

The purpose is front-loaded in the first sentence, and each following clause covers a distinct field with no filler. It is dense but every sentence earns its place, given there is no output schema to document these fields elsewhere.

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 carries the burden of explaining return values and does so for imageUrl, hours, shared, seats, slotMinutes, and untrusted text. It stops short of describing the identifying fields of each space (id, name), so an agent still does not know the full shape of what comes back.

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 100% and the single workspaceId parameter is already fully documented in the schema, including the 'optional only when you belong to exactly one workspace' rule. The description adds nothing about the parameter, so the baseline of 3 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?

Specific verb plus resource: 'List the workspace's active bookable spaces', with the scope narrowed to active/bookable, which rules out archived or non-bookable spaces. It does not name or contrast with the nearest sibling, find_free_rooms, so an agent must infer the boundary itself.

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 no when-to-use guidance: no mention of when to prefer this over find_free_rooms, check_availability, or list_my_workspaces, and no stated prerequisites beyond the workspaceId note already in the schema. Usage can only be inferred from the tool name and purpose statement.

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