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

No annotations are provided, so the description carries the full burden and largely delivers: it discloses the short-lived token on previewUrl, the previewExpiresAt expiry requiring re-polling, and the failure shape with a retryable flag. This is substantial behavioral context beyond the bare 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?

Front-loads the action (poll status) and then enumerates key return fields efficiently. The single long sentence is dense but every clause names a concrete field the agent must relay, so little is wasted.

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 polling tool with no output schema and no annotations, the description compensates well by naming each result field (summary, previewUrl, workspaceUrl, sourceUrl, failure) and the token/expiry lifecycle. An agent has enough to poll, relay, and handle failure correctly.

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 0% for sessionId, and the description doesn't explain what a sessionId is or where to obtain it (presumably from codebase_start_build). Baseline for one required param with no schema docs is 3; more guidance on sourcing the sessionId would push this higher.

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 (poll) and resource (build session status) with explicit scoping to an existing session. An agent can immediately distinguish this from codebase_start_build, codebase_get_build_preview, and codebase_get_deploy_status based on the description alone.

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?

Clear contextual routing: 'Once the build ends, hand the result to your human' and the previewExpiresAt polling loop tell the agent when and how to re-invoke. However, no explicit mention of codebase_get_build_preview as the alternative for preview-specific fetching, so sibling differentiation is implied rather than named.

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