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

Annotations already declare the write/destructive/idempotent profile, and the description adds the crucial non-obvious behavior that an empty string clears a field and that omitting target_user_id writes to the caller's own account. Since destructiveHint=true is declared, a brief note on reversibility of cleared fields would have made it a 5.

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 short sentences: the resource and scope come first, then the mutate-only-what-you-send rule, then the default target. No restatement of schema fields, no filler.

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 6-parameter mutation tool with full schema coverage, rich annotations, and no output schema, the description covers the two things the schema can't: clearing semantics and the default account target. Only the admin-permission consequence and any effect on the live public page are left implicit.

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 schema already documents every parameter, establishing a baseline of 3. The description does add the empty-string-clears convention, but leaves it to the schema to explain the logo_base64 priority over logo_url and the admin-only restriction.

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 (configura) and a concrete resource (o widget embutível no site, página /widget/[userId]) and enumerates the four editable aspects (título, saudação, cor, logotipo). It is clearly distinguishable from set_brand or update_agent_config by resource, though it does not name those siblings explicitly to reinforce the boundary.

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?

"Passe só o que quiser mudar" establishes patch semantics and "Sem target_user_id, altera a PRÓPRIA conta autenticada" defines the default scope, which is exactly the context needed for correct invocation. It does not, however, state when to prefer this over set_brand/update_agent_config or any prerequisites for the admin path.

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