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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false. The description adds valuable context beyond annotations: it is read from public filings, may contain errors, must always show the source link, and must not be presented as personal investment advice. This is exactly the kind of behavioral disclosure needed.

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 a single, information-dense sentence that front-loads the core purpose and then layers details and disclaimers. It is efficient, though the sentence is somewhat long and could be split for readability. Still, no wasted words.

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 tool with one parameter and no output schema, the description fully covers what the agent needs: what is returned (funds, pushes, moves, dates, links), the source (SEC filings), and the required output behavior (show source link, avoid advice). Nothing essential is missing.

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 single parameter slug is fully documented in the schema with an example and a source reference to list_activists. Schema description coverage is 100%, so the tool description adds no further parameter meaning. The baseline of 3 is appropriate.

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 a specific verb ('Describes') and a precise resource ('one large investor') and enumerates the content it returns (funds, pushes, moves, recent filings). It clearly differentiates from list_activists, which lists investors, and other sibling tools that focus on funds or holdings.

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 by the parameter schema (slug from list_activists) and the description's focus on a single investor. It does not explicitly name alternatives or exclusion criteria, but the workflow is clear: you first list activists then fetch details by slug.

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