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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safe-read nature is covered. The description adds value by listing the returned fields (name, ID, timestamp, zone, status, etc.), giving agents a concrete sense of the output. It does not contradict annotations and provides useful behavioral context beyond the structural hints.

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 description is two sentences with no redundancy. The first sentence is a crisp purpose statement; the second provides useful output details and prerequisites. It is well-structured and every sentence earns its place.

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 list operation with an output schema and strong annotations, the description is largely complete. It covers purpose, key output fields, and required inputs. It could be slightly improved by explicitly distinguishing it from get_reservation_details, but the title 'List Reservations Basic Info' partially covers that. The output schema further fills the gap for return values.

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%, meaning all parameters have descriptions in the input schema. The description only repeats that project and zone are required, adding no semantic detail beyond what the schema already provides. Baseline of 3 is appropriate since the schema carries the parameter documentation.

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 clearly states the tool lists Compute Engine reservations, which is a specific verb+resource. It also enumerates the details included (name, ID, creation timestamp, zone, etc.), making the purpose unambiguous. This distinguishes it from sibling get_reservation_* tools that focus on a single reservation.

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 description mentions required inputs (project and zone) but does not explicitly state when to use this tool versus alternatives like get_reservation_basic_info or list_commitments. Usage is implied by the name and listing semantics, but no exclusions or alternative guidance are provided.

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