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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds no behavioral context beyond the schema: no mention of what 'details' include, error behavior for unknown IDs, or whether archived rooms are returned.

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 sentences, zero waste, with the core action front-loaded and the disambiguation guidance following immediately. Nothing redundant or padded.

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 single-parameter read tool with an output schema, full annotation coverage, and explicit sibling routing, everything an agent needs to call it correctly is present. The return payload is defined by the output schema, so the description need not restate it.

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% and the single parameter is fully documented there, so the baseline is 3. The description restates the ID provenance, reinforcing but not extending the schema's meaning.

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 and resource ('Get a room's details by its ID') plus the provenance of the identifier, so an agent knows exactly what it retrieves. It also names the sibling resources it is not (units.listTypes, units.occupancy), making it distinguishable without opening a schema.

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?

Explicitly routes the agent to units.listTypes for room type data and units.occupancy for reserved/blocked dates, and tells where the ID comes from (units.list or a booking's unitId). It stops short of stating when this tool itself is unnecessary versus units.list, but the context is clear.

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