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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context beyond that: the lifecycle state machine and the guarantee that variants, destinations and options are untouched.

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, both front-loaded with the action and scope; the exclusion clause is compact and every phrase carries information. No filler.

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 mutation tool with full annotations, a fully described schema and no output schema, the description covers scope, fields and lifecycle adequately. Return behavior is unspecified but no output schema exists to require it, so the only minor gap is the absence of explicit preconditions.

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%, so the schema already documents tripId, name, status and coverPhoto fully. The description corroborates the fields and adds lifecycle meaning to 'status', which is a marginal gain over the schema baseline of 3.

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?

The description names a specific verb (Change) and resource (top-level trip fields) and enumerates the concrete fields affected: rename, cover photo, lifecycle status. It also explicitly distinguishes this tool from siblings by stating it 'Does not touch variants, destinations or options'.

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?

It provides clear context for the lifecycle transition ('planning -> ready once the plan is settled, finished or cancelled afterwards') and implicitly routes field-specific edits to other tools via the exclusion clause. It lacks an explicit 'use this when / use X instead' statement, but the implied boundaries are strong.

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