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

Beyond the minimal annotations (readOnlyHint=false, destructiveHint=false), the description discloses important behavior: sending an outline makes the reply carry the WRITING BRIEF, and without an account the tool returns a guest_token for later calls and a deck_url for the user. This meaningfully helps an agent anticipate outputs and side conditions, though it could say more about what happens when an account is present.

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 sentences with no filler. The core action and key constraints come first, followed by workflow and return-value context. Every sentence contributes essential information an agent needs to invoke the tool correctly.

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?

Given the complex nested schema and no output schema, the description covers the critical flow-level outputs: the WRITING BRIEF, guest_token, and deck_url. It also connects the tool to the larger two-step deck process. Minor gaps remain, such as explicit account-behavior details and any prerequisites beyond the schema, but the description is largely sufficient for correct invocation.

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%, so the schema already documents every parameter in detail. The tool description adds emphasis on the brand contract ('never guess a colour') and the outline-to-writing-brief relationship, but it does not substantially expand parameter meaning beyond what the schema provides. Baseline 3 is appropriate.

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 ('Start a new presentation') and clearly differentiates this from siblings by framing the two-call workflow: 'this, then submit_deck'. It also makes clear the scope of inputs ('a brief, the brand as YOU know it... and your outline'), so an agent can identify what create_deck does versus write_outline or submit_deck.

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?

The description gives concrete workflow guidance: with an outline, the response carries the WRITING BRIEF, making the whole flow just 'this, then submit_deck'. It also explains the guest case by noting a guest_token and deck_url are returned. It stops short of explicitly saying when not to use this tool versus write_outline or other siblings, but the intended creation flow is clear.

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