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

Annotations already declare the mutation is idempotent and non-destructive; the description adds the key extra fact that the effect is scoped to the connection, which is genuinely useful. It doesn't say what happens to a previously selected brand, whether selection persists across calls, or how the ambiguous-name candidate path leaves state untouched beyond what the schema already says.

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?

Two sentences, zero waste, with the action stated first and the routing rule second. Nothing to trim.

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 2-parameter, no-output-schema tool with full schema coverage, this is nearly complete: action, scope, and preferred usage are all covered. The gap is the relationship to nitro_select_account and whether a brand can be cleared or inspected.

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%, and the schema already explains the name-vs-brand_sid either/or and the ambiguous-name behavior. The description only echoes brand_sid as the thing you'd otherwise pass elsewhere, adding no new parameter semantics.

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?

Specific verb+resource ("Select the current brand") scoped to "this OAuth MCP connection", so the agent knows it sets connection-level state rather than editing a brand record. It does not reference the obvious sibling nitro_select_account, so the differentiation from that tool is left implicit.

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 an explicit routing rule: use this instead of passing brand_sid to other tools. It stops short of stating when not to use it (e.g. after a brand is already selected, or how it interacts with nitro_select_account).

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