brain_stats

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

No annotations are present, so the description must carry behavior disclosure. The listed metrics imply a read-only stats/diagnostic tool, but it never explicitly states that it makes no modifications or whether the embed service health check has side effects/dependencies. This is adequate but leaves the safety profile implicit.

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?

At eight words, the description is highly concise and every listed item adds information about the returned statistics. Its telegraphic noun-phrase style is mildly unpolished but not padded.

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 zero-parameter diagnostic tool with an output schema, the description is largely complete: it enumerates the available statistics and implies the read-only nature. It could add an explicit 'use for health/usage checks' clause, but an agent can safely invoke and interpret this tool from the current definition.

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?

The tool takes zero parameters, so there is no parameter semantics burden. Per the 0-params baseline, the description does not need to compensate for any schema gaps.

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 names a specific resource (brain collection stats) and the concrete metrics included: size, disk usage, embed service health, and .md count. It lacks an explicit verb like 'returns' or 'reports', but the noun-phrase list is specific enough to distinguish this from sibling read/search/list tools.

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?

Usage is implied: an agent needing aggregate collection statistics or service health would know to call this tool. However, there is no explicit when-to-use or when-not-to-use guidance, and no differentiation from brain_list or brain_search, which could also be considered for data collection questions.

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