brain_status

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

With no annotations, the description carries the disclosure burden and does well: it reveals that the tool reports background worker state, failure reasons, and an ETA, which tells the agent this is an informational read, not a mutation. It stops short of explicitly declaring it side-effect-free or stating whether querying has any cost.

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, front-loaded with the core question and purpose, followed by the return contents and then the usage directive. 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?

An output schema exists so return values needn't be spelled out, and for a one-optional-param status check the description is nearly sufficient. The only real gap is the behavior when 'creator' is omitted.

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 0% and the single 'creator' parameter is nullable with a null default, yet the description never says whether omitting it returns global status or errors. The phrase 'how much of a creator is ready' only weakly implies that the parameter scopes the report to one creator.

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 opens with a specific question ('How complete is the brain?') and then enumerates exactly what the tool returns: label, percent built/searchable, percent analysed, worker state, failures with reasons, and rough ETA. This is clearly distinct from siblings like rebuild_brain, pause_brain, or brain_doctor.

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?

It states a concrete when-to-use: 'tell the user how much of a creator is ready before relying on search results.' That ties the tool to a real decision point. It does not, however, explicitly contrast with brain_doctor (also a diagnostic tool) or say when to prefer the status check over a rebuild.

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