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

With readOnlyHint=true already covering the safety profile, the description adds genuinely new context: default sort order ('newest first'), the set of result fields (status, timestamps, duration, cache time saved, cached vs total steps), and the backing service ('core BuildService/ListBuilds'). It does not mention pagination behavior or result limits, but it goes meaningfully beyond the annotation.

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?

A single front-loaded sentence followed by a compact service breadcrumb; the returned-field list is dense but earns its place as payload preview. Slight bloat from the trailing service reference, but nothing extraneous.

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 read-only list tool with no output schema, the description adequately enumerates what comes back and the ordering, and the schema documents paging. It omits mention of the nextPageToken in the response, so an agent learns that only from the input schema's page_token text, a minor gap.

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%, including the reference chain 'Project id, from depot_list_projects' and the page_token cursor semantics, so the schema carries all parameter meaning. The description adds no further syntax or format detail beyond what the schema already provides, making 3 the correct baseline.

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 default ordering, which clearly separates it from depot_get_build (single build) and depot_ci_list_runs (CI runs). It stops short of explicitly naming those siblings, so an agent must infer the boundary rather than being told.

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 implies the use case (browsing a project's builds, newest first) but never states when to prefer this tool over depot_get_build, depot_get_build_steps, or depot_ci_list_runs, and gives no prerequisites or exclusions. Usage is inferable but not guided.

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