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

Annotations already cover read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description adds genuinely new context: the download is gated behind a membership benefit and accounts without one receive an explanatory response rather than a link.

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 short sentences with the core action front-loaded and the key requirement last. Slightly awkward phrasing ('Answer the download link') but no padding or repetition.

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 two-parameter lookup with no output schema, the description covers the input keys, the id source, and the entitlement failure mode. It leaves minor gaps such as whether the returned link expires, but nothing essential to correct invocation 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%, so the baseline is 3, but the description adds a real semantic point the schema omits: the tool accepts either logo_id or kit_id as an alternate key, even though the schema declares no required parameters.

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: retrieves the download link for a ready brand kit's zip file. It also names the two lookup keys and points at list_brand_kits as the id source, which separates it cleanly from get_brand_kit and list_brand_kits.

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?

Explains that the caller passes either logo_id or kit_id and where those ids come from, and the word 'ready' implies the kit must be finished. It does not explicitly say when to prefer this over get_brand_kit or what happens for a not-yet-ready kit, so it stops short of full routing guidance.

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