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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds genuine behavioral value by disclosing what the payload contains (phase, step checklist with the tool that records each step, readiness to go live, and settings requiring user confirmation), which is beyond what the annotations provide.

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 leads with the core action and then lists the returned fields efficiently, with no filler. The inline enumeration is dense but each item earns its place by describing a distinct piece of state.

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?

With no output schema, the description carries the burden of describing return values and does so thoroughly (phase, checklist, readiness, depth, pending settings). Safety is covered by annotations, and the only missing element is routing against sibling activation tools.

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?

Only one parameter exists and its schema description coverage is 100% ('Brain id or name. Defaults to the active brain.'). The description adds no parameter-level information and does not mention the active-brain default, so the schema does the work and the baseline of 3 applies.

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 states a specific verb and resource ('Returns the state of building a brain from the user's sources') and enumerates the returned content (phase, checklist, readiness, depth, settings). It is clear in isolation, but it never differentiates itself from the closely related siblings activation_report and activation_stage, so an agent cannot easily tell which status tool to pick.

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?

There is no explicit when-to-use guidance, no prerequisites, and no mention of alternatives such as activation_report or activation_stage despite their near-identical naming. The usage is only inferable from the returned content, leaving the agent to guess which activation tool to call.

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