stats

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

With no annotations provided, the description carries the full burden of behavioral transparency. It states the tool returns a summary, which likely is read-only and non-destructive, but does not explicitly confirm this or disclose any potential side effects, performance implications, or access requirements.

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?

The description is extremely concise at four words, front-loads the key information ('Index health summary'), and specifies exact metrics. Every word serves a purpose with no redundancy.

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?

Given the tool has no parameters and no output schema, the description is adequate but could be more complete by describing the return format (e.g., JSON structure, whether it returns aggregate or per-index stats). It does not explain coverage scope or interpretation, which may be needed for effective use.

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 has zero parameters, so the schema provides complete coverage. The description does not need to add parameter details. Baseline is 4, and no additional value is required.

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 clearly states the tool provides an 'index health summary' with specific metrics: message/session counts and coverage. This is distinct from sibling tools like list_sessions (lists sessions), recent (recent items), reindex (performs reindexing), search (search query), and session (specific session operations).

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?

The description implies usage for obtaining health statistics, but does not provide explicit guidance on when to use this tool versus alternatives, nor does it mention conditions for use or non-use. The purpose is clear, but the lack of exclusions or comparisons leaves some ambiguity.

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