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

Annotations already declare readOnly, idempotent, destructive=false, and openWorld=false, so the safety profile is covered. The description adds meaningful behavior beyond that: the report is generated weekly, checks the first 500 sitemap URLs, and reading does not trigger generation. This cadence/scope detail is genuinely additive, though the key point is stated twice rather than expanded.

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?

The content is reasonable in length, but 'Reading never runs the report' is duplicated verbatim at the start and the end, wasting a full sentence. The middle sentence packs scope and cadence well, but the redundancy undercuts tightness.

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 convey return content, and it does: it lists what the report contains (new and fixed problems, new pages, competitor pages). Combined with annotations covering safety and 100% schema coverage on inputs, an agent has enough to call it correctly, though the report's exact format remains unspecified.

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 100% ('id' = site owned by the account, 'lang' optional for Portuguese), so the schema fully documents both parameters. The description adds no syntax, format, or meaning beyond what the schema provides, which is the baseline when the schema does the work.

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 and resource ('Read the weekly report of a site') and enumerates its contents (changes since last week, competitor new pages, findings). Clear enough to distinguish the read action from generating a report, but it never names or contrasts with siblings like weekly_site_report_history or save_weekly_site_report.

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 repeated 'Reading never runs the report' implies this tool reads an existing report rather than generating one, which is useful context. However, no explicit when-to-use/when-not guidance or alternatives are given, so the routing to weekly_site_report_history or save_weekly_site_report is left to inference.

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