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

Beyond the annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=false), the description discloses the target library, default project behavior when no project is named, that there is 'no link to open and nothing for them to press', the returned fields (asset_id, revision for edit_asset, open_url), and the full auth failure/remediation path. This is unusually rich behavioral context.

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?

The when-to-use clause is correctly front-loaded, but the closing paragraph embeds lengthy per-agent sign-in remediation (Claude Code /mcp instructions, Codex command, 'other agents open the sign-in page themselves'). Actionable, yet disproportionate to a one-parameter tool and dilutes the core message.

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 correctly compensates by naming the return values, and it covers the auth prerequisite and side effects. The only shortfall is the stale project_id/same_project_as reference that contradicts the one-parameter schema.

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% for the single 'handle' parameter, so the baseline would be 3, but the description instead references 'project_id or same_project_as' as if they were inputs — neither exists in the schema. That misdirects an agent toward parameters it cannot pass, which is worse than adding no parameter detail.

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?

The description uses a specific verb and resource ('Saves it straight into their appdesigns library') and situates it precisely in the workflow: after finish_project/update_project or create_design/update_design. It is clearly distinguishable from the adjacent save/update siblings (create_design, update_design, edit_asset).

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?

It states exactly when to call ('when the user is signed in and a set you made is ready ... once the previews look right') and names the upstream tools that must run first. It also gives an explicit precondition (user signed in to appdesigns) with the alternatives for what happens without it.

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