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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered structurally. The description adds real behavioral value beyond that: it explains the stage lifecycle, the 0-100 progress ranges, and crucially that an unfinished build has no site link while a complete one exposes previewUrl. That completion-state nuance is not inferable from annotations or 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 core purpose and return fields, with parameter selection and the watchUrl aside following in logical order. The parenthetical enumeration of all seven stages is slightly long but earns its place by defining the stage vocabulary.

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?

There is no output schema, so the description must carry return-value semantics itself, and it does: it names every field an agent needs to interpret a status response and explains the previewUrl/isComplete relationship. For a two-param read-only polling tool this is complete.

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 coverage is 100% and both parameter descriptions already say 'preferred for progress tracking' and 'fallback, less detailed', so the description's versionId/businessId guidance largely restates the schema. It adds only the mild nuance of 'most detail' vs 'less detailed', which is the baseline-3 case where the schema does the heavy lifting.

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 (Reports) and resource (progress of a build_website build), then enumerates the exact fields returned (stage, overallProgress, stageProgress, status, isComplete). It explicitly ties itself to the sibling build_website as the producer of the IDs, so an agent can distinguish it from host_site/host_zip/etc. without opening any schema.

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?

Clearly frames the two ways to call it (versionId for most detail, businessId as a less-detailed fallback) and points to watchUrl as a live alternative view. It stops short of stating when NOT to poll this tool or how often, so it is clear context rather than exhaustive routing guidance.

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