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

With only destructiveHint/title in annotations, the description carries real weight and delivers: it labels the operation as WRITE, discloses name-based idempotency and the returned-project behavior on collision, and lists the default cache/hardware configuration. It does not mention auth/org-token requirements or side effects like builder provisioning, so it stops short of a 5.

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 operation type ('WRITE.') followed by purpose, then idempotency semantics, then defaults — four tight clauses, each earning its place, with 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 an 8-parameter, 2-required creation tool with no output schema, the description covers purpose, write semantics, idempotency and defaults adequately; only the return shape and permission/org-token prerequisites are left implicit, which the schema partially covers via organization_id.

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 baseline is 3; the description's default recap (50 GB / 14 days / HARDWARE_16X32) largely restates what the schema already documents per-parameter and adds no format or interaction detail beyond that.

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 ('Create a Depot container-build project') plus a clarifying gloss ('an isolated build cache'), which cleanly separates it from depot_get_project, depot_list_projects and the build/CI siblings.

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 idempotency note ('if an active project with the same name exists, that project is returned') implicitly tells the agent it can call this without a prior lookup, but there is no explicit when-to-use/when-not guidance or named alternative such as depot_get_project for read-only lookup.

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