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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and network scope are covered. The description adds genuinely new behavioral context: it fetches exactly one page per call and the response shape varies by page type (section links vs. archive dates vs. day links vs. article URLs), which tells the agent to expect heterogeneous results and to iterate. It does not mention rate limits or pagination limits.

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 with zero redundancy, and the core action plus return-shape summary is front-loaded before the input-provenance hint.

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?

With an output schema present, the description needn't enumerate return fields, and it still summarizes them. Annotations cover the safety profile, the schema covers the parameter, and the description covers input provenance and the one-page-per-call traversal model — nothing an agent needs to invoke it correctly is missing.

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 the single parameter's schema description ('Canonical shopping.yahoo.com sitemap page URL from /yahoo-shopping/sitemaps or a prior response') is nearly identical to the description's guidance. The description adds no format or validation detail beyond the schema, so 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?

Specific verb ('Fetch') plus a precisely scoped resource ('one canonical Yahoo Shopping sitemap page by URL'), and it enumerates the payload variants an agent can expect (section links, archive dates, day links, article URLs). It is clearly separable from yahoo_shopping_sitemaps, which is the index tool that supplies the URL.

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?

Explicitly states where the input URL comes from ('a URL from yahoo_shopping_sitemaps or a previous page response') and that it is used 'to read a specific archive', which conveys the intended traversal workflow. It stops short of stating when not to use it (e.g. don't use it to discover the sitemap index), so it is strong but not exhaustive.

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