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

Beyond the annotations (readOnlyHint, idempotentHint), the description adds valuable behavioral context: results are informational, read automatically from public filings, may contain errors, and the agent must show the source link and avoid presenting results as investment advice. This is a meaningful addition that helps the agent handle results responsibly. No contradiction with annotations.

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 two sentences long and front-loaded with the core purpose and output format, followed by caveats. It earns its place, though the second sentence could be tightened. Overall it is appropriately structured and not bloated.

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?

The description covers the return format (plain sentences with dates/links), data source (SEC filings), error potential, and usage constraints. Given there is no output schema and only two simple parameters, this is essentially complete for an agent to call the tool 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?

Both parameters (days, cef_only) already have complete descriptions in the input schema (100% coverage). The tool description does not add any new meaning or context for these parameters, so the baseline score 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 clearly states the tool lists the newest notices from large investors about owning 5% or more of a fund, including the types of actions (raised, cut, passive, sold down) and the output format (one plain sentence with as-of dates and source links). This specific verb+resource description distinguishes it from sibling tools like list_events or get_fund_events, which focus on different event types or fund-specific data.

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: an agent should call this when wanting recent SEC filings from large investors about stake changes. However, it provides no explicit guidance on when to choose this over alternatives (e.g., list_events for general events or get_fund_holdings for current positions), and no exclusionary conditions are stated.

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