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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive behavior. The description adds meaningful context beyond that by clarifying the dataset is a current subset and by framing the tool as a freshness/comparability check, which helps an agent set expectations about temporal scope.

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, no filler. The coverage scope is front-loaded and the usage guidance follows immediately, each sentence earning its place.

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 status/coverage tool with read-only and idempotent annotations, the description is complete: it tells the agent what data will be returned and why that matters before using dependent tools. No output schema is required to make the call safely and correctly.

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 the description carries no parameter documentation burden. The empty input schema with an empty example and 100% schema coverage confirms no inputs are needed, and the description focuses on what output to expect instead.

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 the tool reports what the 13F dataset currently covers, specifically SEC release windows, reporting quarters, filing counts, holdings rows, and total size. This clearly identifies the resource and scope, and it differentiates itself from sibling tools like manager_changes and security_flows by positioning coverage as a prerequisite check.

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 explicitly says to use this tool to check freshness and to know which quarters manager_changes/security_flows can actually compare before relying on ownership answers. This gives concrete when-to-use guidance and names the dependent sibling tools, making the decision obvious.

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