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

Annotations already declare idempotent=true, destructive=false, readOnly=false, so the safety profile is covered; the description adds real context beyond them — bounded 1-5 future slots, an email-verification precondition, and optimistic concurrency via expectedVersion. It still omits what happens on a version mismatch and what replaceProposalIds removes, which is the main behavioral gap for a mutation tool.

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?

A single dense sentence with the action front-loaded and every qualifier carrying information about a constraint. Nothing is padded or repeated from the schema.

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?

An output schema exists, so return values need not be explained, but for a five-parameter mutation with 0% schema coverage the description should account for replaceProposalIds and the conflict behavior on stale version. As written, an agent could call it correctly only by guessing at those two aspects.

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 0%, so the description carries the full burden. It explains the slots count bound, expectedVersion ('exact version'), and the nature of idempotencyKey ('durable'), but never mentions sessionToken or replaceProposalIds, leaving two of five parameters with no meaning beyond their type.

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 (propose viewing slots) plus hard scope (one to five, future, bounded, from an email-verified application). An agent can tell this is the tenant-side proposal action rather than a landlord-side one, though no sibling such as viewings.set_availability or viewings.respond_to_proposal is named to sharpen the contrast.

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?

Preconditions are embedded ('email-verified application', 'at its exact version'), which implies when the call is legal, but there is no explicit when-to-use versus viewings.set_availability, viewings.respond_to_proposal, or viewings.cancel, and no stated exclusions or failure conditions.

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