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

Annotations already declare readOnlyHint=true, so safety is covered; the description adds meaningful behavior beyond that by disclosing the bounded blocking wait (up to 25s) for running scans and by previewing the returned payload despite there being no output schema. It stops short of covering output format details or rate limits, keeping it a solid but not exhaustive 4.

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 sentences, front-loaded with the purpose and followed by the operational tip; no filler. The enumerated return list is dense but earns its space given the absence of an output schema.

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 tool with full schema coverage and a readOnlyHint, the description supplies what the structured data cannot: expected return content and the bounded-wait polling pattern. Nothing essential to calling it correctly is missing, though a note on whether waiting is required versus optional polling would close the last 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 coverage is 100%, so both parameters (including the 0–25 range and default of 0 for wait_seconds, and the provenance of scan_id) are already documented in structured fields. The description restates the wait cap and the scan-summary fields but adds no syntax or edge-case meaning beyond the schema, so the baseline 3 applies.

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?

The description opens with a specific verb+resource pairing — status/progress/summary of a scan — and enumerates the concrete data it returns (score and band, category scores, Domain Rating, top issues), so an agent knows exactly what this call yields. It does not explicitly contrast itself with scan_site or list_scans, though the scan_id schema note points back to them.

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 second sentence gives actionable polling guidance: set wait_seconds (max 25) to block until a running scan finishes, which tells the agent how to handle in-progress scans. However, it never states when to reach for this tool versus list_scans (enumerate scans) or scan_site (start one); that routing is only implied by the schema hint on scan_id.

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