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

Annotations already declare destructiveHint=true, readOnlyHint=false, and idempotentHint=false, so the safety profile is covered. The description's 'replace' wording is consistent with the destructive hint, but it adds no further behavioral detail (what happens to the prior asset, auth needs, limits). With annotations carrying the burden, this is adequate but thin.

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?

A single front-loaded sentence with zero filler that captures both the add and replace cases. Nothing is wasted.

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 mutation tool with no output schema, the description covers the core action but omits return behavior and replacement consequences. Annotations cover the safety profile, so it is minimally sufficient rather than 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 75%, so the schema already documents base64, brand_kit_id, and asset_id in detail. The description only restates the asset_id add/replace role that the schema already explains, adding no syntax or format meaning beyond it. 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?

States specific verbs (add/replace) and the resource (logo or font in a brand kit), and the asset-ID mechanism distinguishes it from siblings like upload_image_asset and create_brand_kit. It is clear, though it does not explicitly name an alternative tool to route away from.

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 add-vs-replace distinction (omit asset_id to add, supply it to replace) is implied by 'or replace one by asset ID,' but the schema already states this. There is no explicit guidance on when to use this over upload_image_asset or other asset tools, so usage is only implied.

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