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

Annotations only say destructiveHint=true and idempotentHint=true; the description explains *why* — empty string wipes a field, unspecified fields are preserved, logo_base64 takes priority over logo_url and is capped at 400 KB, and target_user_id requires platform-admin rights. That is exactly the mutation, overwrite, and authorization context annotations cannot convey.

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 core mutation rules (partial update, clearing, logo source, admin targeting) appear in the first two sentences before elaboration. Slightly padded by the explanatory 'é o que faz a plataforma aparecer com a marca do cliente' clause and an emoji prefix, but no sentence 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 7-parameter, all-optional mutation with no output schema, the description covers partial-update semantics, clearing, format choice, size limit, and admin targeting. Remaining gaps are minor: no mention of what happens with an invalid font_family or a failed base64 upload, and no success response expectation.

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 a real semantic not in the schema: an empty string is a clear instruction rather than a no-op. It also restates the URL-or-base64 choice for the logo, which is largely redundant with the schema, keeping it below a 5.

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 concrete verb and resource: it sets the colors, font, and logo the account uses across the internal panel and client portal, and explains the effect (white-label appearance). It does not explicitly name siblings such as get_brand or set_widget_config, so an agent must infer the boundary, but the resource is unmistakable.

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 clear operating context: send only the fields you want to change, the rest stay as-is, empty string clears a field, and target_user_id is admin-only and defaults to the caller's own account. It lacks an explicit 'do not use this to read brand settings — use get_brand' routing statement, so it stops short of full alternative guidance.

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