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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so safety is covered; the description adds the operationally critical context that nothing is actually booked, no seat held, no personal or payment details taken, and the user completes on the enrolment site. That prevents an agent from falsely telling a user they are booked — information no annotation conveys.

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 core action is front-loaded in the first sentence, followed by the handoff flow, the critical "this tool books nothing" warning, and the group exception. No sentence is filler — each one guards against a plausible agent error.

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-value explanation is unnecessary; the description covers the input source, downstream user flow, capability limits, and the group alternative. Nothing an agent needs to call and message correctly is missing.

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 parameter is fully documented in the schema itself ("The session_id from a search_sessions or search_nearby_sessions result"). The description reinforces the provenance of the id but adds no syntax, format, or constraint beyond what the schema already provides, so the baseline 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?

States a specific verb and resource ("Get the link that books one place in a session") and immediately names the sibling tools that produce the required input, search_sessions and search_nearby_sessions. An agent can distinguish this from the search tools without opening any 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 states where the session_id comes from, what to do with the result (give the link to the person), and the exclusion case for groups ("book each person separately or use the corporate enquiry page"). Both the when and the when-not are covered.

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