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

Annotations already declare readOnly/idempotent/openWorld/non-destructive, and the description adds genuinely new behavioral detail: per-URL confidence scoring, flagging of unmatched URLs with suggestions, and concrete output formats. The phrase 'write the redirect rules' is slightly at odds with readOnlyHint, but since the rules are emitted as text rather than applied, this reads as generation, not mutation.

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?

Purpose is front-loaded in the first clause, followed by inputs, output behavior, and the verification handoff. The single long first sentence is dense but every clause carries information; only minor trimming would be possible.

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?

An output schema exists, so return-value explanation is not strictly required, yet the description usefully summarizes the output shape (confidence scores, flagged unmatched URLs, format choices). Combined with annotations, an agent has enough to invoke it correctly, with only the input-precedence rule (list vs site) left implicit.

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 60%, and the description compensates by explaining that old/new URLs can be supplied either as a list or as a site address whose sitemap will be read. It also ties the 'redirects' format to Cloudflare Pages and Netlify (_redirects), adding meaning beyond the enum label.

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: matches old URLs to new ones and generates 301 redirect rules for migrations/restructures. It is distinguishable from siblings, and it explicitly names check_urls as the post-live verification step, so the agent can route correctly.

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?

Gives clear context for when to use it (site migration or restructure) and routes the agent to check_urls for post-deployment verification. It lacks an explicit 'when not to use' clause, but the alternative and its condition are stated, which is close to full coverage.

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