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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, so the safety profile is covered. The description adds genuinely new behavior — that requesting target=published on a never-published site fails with 404 — plus the shape of the returned data (no output schema exists). It stops short of auth needs, rate limits, or whether the call triggers/awaits a build.

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?

Two dense sentences with no filler: the payload is front-loaded, and the error condition is stated last where it belongs. Nothing repeats the name or annotations.

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 two-parameter read with full annotation coverage and no output schema, the description covers what is returned and the main failure mode, which is close to sufficient. The remaining gap is how it relates to adjacent tools (summary_get, head_check, deployment_ensure) and whether it is safe to poll.

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%, so the description must carry the parameters. It does explain both meanings of target (head vs published) and the failure mode of one value, which is the meaningful part. websiteId is left entirely to the schema, though its name and minLength make it largely self-explanatory.

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 (returns) and resource (deployment build status) and enumerates what comes back: preview revision, page routes, publish availability, build state, scoped to head or published version. It is clearly distinguishable from mutation siblings, though it never explicitly contrasts itself with nearby reads like websiteSourceCode_summary_get or websiteSourceCode_head_check.

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?

Usage is only implied: the phrase 'selected head or published source version' tells the agent which target to pick, and the 404 note warns about one edge case. There is no when-to-use guidance relative to sibling reads (summary_get, head_check) or deployment_ensure, and no preconditions are stated.

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