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

Annotations declare readOnlyHint=true, so the safety profile is already known. The description adds meaningful behavioral context: institutional holdings are sorted largest first, activist mode shows 13D stakes, and by_activist treats entity as a holder name. This goes beyond what annotations alone convey, though it does not discuss limit behavior or output details.

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 front-loaded with a one-sentence purpose, then organizes the view modes into a scannable list with aliases and behavioral notes. Every sentence adds value, and the closing sibling reference is useful without being verbose.

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's moderate complexity, an output schema, and readOnly annotations, the description covers all essential aspects: the three modes, alias resolution, entity semantics, sorting behavior, and the relevant sibling tool. Nothing an agent needs to correctly invoke this tool 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?

Schema description coverage is 0%, so the description must compensate for the schema's silence. It thoroughly explains the view enum including aliases and the meaning of entity in each mode. The limit parameter is left undocumented, but the overall parameter semantics are substantially clarified beyond the bare schema.

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's purpose: determining who owns a stock and the activist picture. It goes beyond the name by enumerating three distinct views and explicitly distinguishes itself from get_holdings, making its scope unambiguous.

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 provides explicit guidance on which view to use for which question and names the sibling alternative get_holdings for a different use case. This gives an agent concrete decision criteria rather than leaving usage to inference.

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