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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, non-open-world), so the bar is lower. The description adds genuine behavior beyond them: the sign-in flow for unauthenticated viewers, the banner naming the key that made or last changed the design with one-click revert to the previous state, and that zero arguments yields a blank editor.

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 purpose and return value, then layers routing and fallback behavior. It runs long, and the banner/key-revert detail is slightly tangential, but nearly every sentence carries actionable routing or behavioral information.

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?

There is no output schema, and the description fully describes what is returned (a URL), the variants (design-specific vs. blank editor), and the auth implications. Nothing needed to invoke 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 coverage is 100%, so the baseline is 3, but the description adds real meaning: designId scopes the URL to the owning account or team and makes it load that specific design, while its absence returns a blank editor. That is more than the schema's bare 'A cloud design id from create_design or list_designs.'

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 ('Return the URL that puts a design in front of a person on the canvas') and explicitly distinguishes itself from create_share_link, the closest sibling. An agent can identify the tool's role without opening the 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?

Gives explicit when-to-use ('belongs at the end of every workflow: an agent produces, a human reviews and approves') and when-not-to-use ('For someone WITHOUT an account ... use create_share_link instead'). It also warns that create_design and update_design already return the same link, so the agent knows when this tool is redundant.

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