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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered; the description adds real value by disclosing that results are paged and that the job must be complete first — a failure mode the agent would otherwise hit blind. It stops short of describing pagination termination or error behavior, so not a 5.

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?

Three compact sentences with zero filler; the return contents come first, the sibling alternative and precondition follow. Every clause carries information an agent needs.

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 no output schema, the description does the work of sketching the return shape (data, result, flags, suggested_correction, address info) and names the completion precondition. The one soft spot is "address info," which is left unexpanded, but nothing essential to invoking 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 description coverage is 100% and the page parameter's description already explains passing the previous reply's next_page, so the schema carries the parameter burden. The description only adds the word "Paged" and adds no format or constraint detail beyond the schema — 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?

States a specific verb and resource and, unusually, enumerates what each result row contains (submitted data plus verification fields). It also explicitly distinguishes itself from neverbounce_download_job_results, so an agent can separate the two sibling tools without inspecting schemas.

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 an explicit alternative and the condition that selects it ("use neverbounce_download_job_results for a CSV") plus a hard precondition ("The job must be complete"). That covers when-to-use, when-to-use-something-else, and the prerequisite in one line.

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