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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful context beyond them: nothing is stored or sent, the caller must upload the returned HTML, and there is a 500-domain ceiling. It stops short of describing the returned location format, but the output schema likely covers that.

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 action, then adds return/upload behavior, the limit, and the alternative in tight succession. Every sentence carries distinct information with no redundancy or filler.

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 generation tool with an output schema, the description covers the essential behavioral facts an agent needs: no server-side persistence, caller-uploads responsibility, the 500-domain bound, and the sibling alternative. Nothing material to correct invocation appears 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%, so the schema already documents email, domains, and note with types and limits. The description reinforces the shared-email concept and the 500-domain cap but adds no syntax or format detail beyond what the schema provides. Baseline 3 is appropriate.

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 (generate) and resource (one index.html for-sale page for every parked domain in a portfolio), including the shared offer-email behavior. It explicitly distinguishes itself from the sibling set_listing_terms, so an agent can select it without opening either 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?

Names an alternative and the condition that selects it: 'Use set_listing_terms instead to set terms on a domain already listed on this market.' This is clear routing context, though it does not enumerate other conditions (e.g., single-domain scenarios or overlap with read_for_sale_page).

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