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

Annotations already declare readOnly/non-destructive/non-openWorld, so the bar is lower; the description still adds real value by disclosing the Authorization: Bearer requirement, the CLI invocation (`koppar download <design> <artifact>`), and that only currently-available artifacts are returned. It doesn't say whether URLs expire or how availability is signaled, keeping it out of 5 territory.

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 tightly-packed sentences with the artifact list and availability caveat front-loaded, followed by the auth/CLI detail. No filler sentences and no repetition of structured fields.

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 simple read-only single-parameter tool, the description covers what is returned (URLs plus availability) and the auth/CLI path, which is sufficient without an output schema. A note on URL lifetime or the response shape would push it to complete.

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% with a single fully-described design_id, so the schema carries the parameter meaning and baseline is 3. The description adds no extra semantics (e.g., how design_id relates to artifacts or the artifact selector for the CLI) beyond what the schema already states.

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+resource (retrieve download URLs for a design) and enumerates the artifact types covered, which is more than a bare restatement of the name. However, it doesn't explicitly distinguish itself from overlapping siblings like get_bom or export_step, which also surface design artifacts, so the agent must infer the difference.

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?

Usage is implied (fetch links to artifacts) and it adds practical context about auth and the CLI equivalent, but there is no explicit when-to-use/when-not clause or routing to alternatives such as get_bom, export_step, or get_review_packet. The agent gets context but no decision rule.

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