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

Annotations already establish readOnlyHint=true, so safety is covered. The description adds real value beyond that by disclosing the returned fields (status values, timestamps, duration, cache time saved, cached vs total steps), which matters because there is no output schema.

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?

One dense sentence with the resource and ordering front-loaded, followed by a short backend-reference trailer. Efficient and well-ordered, though the 'Depot: core BuildService/ListBuilds' clause is largely decorative.

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 compensates by enumerating the returned fields and status values, and pagination semantics live in the schema. Complete enough for an agent to list builds correctly; only the when-to-use routing is thin.

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 project_id, page_size and page_token are already documented in the schema, including that project_id comes from depot_list_projects. The description adds no parameter-level detail beyond reinforcing project scoping, matching the baseline 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?

States a specific verb and resource (list container builds in a project) plus an ordering guarantee (newest first), which cleanly separates it from the singular depot_get_build. It stops short of naming a sibling tool to route against, but the purpose is unambiguous.

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 scope phrase 'in a project' implies you need a project and that this is the collection-level listing, but there is no explicit when-to-use guidance, no mention of depot_get_build/depot_get_build_steps for single-build or step-level detail, and no exclusion guidance.

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