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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds useful context beyond annotations: authentication and user scoping ('authenticated user's') and that the response includes statuses for each build. It does not describe pagination or empty-result behavior, but the schema already provides limit details.

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 sentence with no filler. The verb and resource are front-loaded, and the clause 'with their statuses' adds return-value context that helps the agent understand the operation's purpose.

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 simple read-only list tool with one optional parameter and no output schema, the description is largely complete: it states user scope, resource type, recency, and returned fields. The only gap is not explicitly routing to get_build_status for single-build lookups, which is minor given sibling names are visible.

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?

Input schema covers the only parameter (limit) fully with type, default, and max, so the description need not repeat it. Baseline 3 applies; the description offers no additional parameter semantics beyond the schema.

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 ('List'), resource ('the authenticated user's recent PromptUI builds'), and what is returned ('with their statuses'). The plural 'builds' and inclusion of statuses clearly differentiate it from sibling get_build_status, which implies a single build lookup.

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 when to use this tool: to enumerate recent builds and their statuses. However, it does not explicitly mention the obvious alternative get_build_status or give an exclusion, leaving the agent to infer the distinction between listing and fetching a single build's status.

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