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

With no annotations, the description carries the full burden and does disclose useful output behavior: results are grouped by period with normalized members, object_id is only valid where detail_available=true, percentages may be null, and *_raw preserves source text. These quirks are helpful and not derivable from the schema, though pagination/limits are unmentioned.

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?

Compact and front-loaded: scope first, then return-shape notes. Every sentence carries information, though the object_id note is slightly ambiguous since it references an output field the agent has not yet seen.

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?

With no output schema and no annotations, the description does describe the return grouping and null/raw caveats, which is valuable. However, it leaves gaps: whether results are paginated, how many periods are returned, and what 'normalized members' concretely contains.

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 100%, so both parameters (type, symbol) are already documented in the schema. The description's mention of object_id pertains to a return field, not an input parameter, so it adds no parameter meaning beyond the schema baseline.

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?

States a specific verb and resource (major shareholder holdings) and clarifies scope: 'across reporting periods, not only the top ten.' This meaningfully distinguishes it from get_shareholders_latest and get_shareholder_detail, though it never names those siblings explicitly.

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 phrases 'across reporting periods' and 'not only the top ten' implicitly signal when to prefer this over a latest-only or top-ten-only variant, but no alternative tool is named and no explicit when/when-not condition is given. Usage must be inferred from the sibling list.

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