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

Annotations already establish that this is a non-destructive, closed-world mutation (readOnlyHint=false, destructiveHint=false, openWorldHint=false). The description adds useful behavior beyond that: it returns an opaque resume credential plus a trusted-desktop browser task and deliberately stops before any booking or payment action. It does not cover credential lifetime, reuse, or failure modes, which is the main remaining gap.

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 zero padding; the creation action and its return artifacts come first, and the exclusion list follows immediately. Every clause carries information an agent needs.

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 correctly takes on the burden of explaining return values (opaque resume credential, browser task) and the mutation's deliberate limits. However, for a 3-parameter tool at 0% schema coverage, the absence of any parameter guidance leaves the caller under-equipped to construct a valid invocation.

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 all three required parameters (search_id, property_id, selection_token) are undocumented in both schema and description. The phrase 'selected actual customer record' hints that selection_token ties to a prior discovery step, but no format, provenance, or expiry is given for any 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?

States a specific verb and resource: 'Create a Spann journey for the selected actual customer record,' and adds what it does not do (execute browser, book, pay). It is distinguishable from siblings like get_spann_journey_status and prepare_reservation_action, though it never explicitly names the boundary versus prepare_reservation_action.

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 negative scope clause ('does not execute a browser, fill guests, accept terms, book or pay') effectively tells the agent when this tool stops and something else must take over, which is real when/when-not guidance. It stops short of naming the specific follow-up sibling tool, so the routing remains partly inferential.

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