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

Annotations carry destructiveHint=true, so the safety bar is lower, but the description adds genuinely useful non-structured context: it holds inventory while open and commits nothing until create_booking returns a session_id to reuse. It does not spell out what happens to held inventory on abandonment or expiry, which would be the remaining valuable disclosure.

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?

Front-loaded with the three supported operations and the key safety fact ('NOTHING is booked until create_booking') in the same breath. It is dense and slightly run-on with parentheticals, but every sentence carries information.

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 states the return value (session_id to reuse) and the post-call state (inventory held, not booked). For a 4-parameter nested-object mutation tool it covers the essentials; error and expiry behavior are the only notable gaps.

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%, so the baseline is 3, but the description adds semantics the schema lacks: where SLIP strings originate (a rated get_item call) and the combination rule that line_id + a single slip replaces an existing line. The alter value semantics are largely redundant with the schema.

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 (start/modify a booking session) and enumerates the three operations it supports: add SLIPs, replace a line, alter lines. It also names the terminal sibling checkfront_create_booking, so an agent can tell what this tool does NOT do 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?

Gives clear workflow context: SLIPs come from a rated checkfront_get_item / checkfront_list_items call, and nothing is booked until checkfront_create_booking. That routes the agent correctly between session-building and committing. It does not mention end_booking_session or get_booking_session as alternatives, so it stops short of full when/when-not guidance.

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