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

Annotations only declare readOnlyHint, so the description carries the rest and delivers: no ticker field, cusip stripped on every channel, position_type must not be summed, SEC EDGAR source with ~45-day delay, heavy operation capped at 2 concurrent, and caveats surfaced via tool_notes. This is rich disclosure beyond the schema.

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?

Front-loaded with the core purpose and dense with distinguishing constraints; nearly every clause earns its place. It is long and packs several concerns into one paragraph, which slightly hurts scannability, but there is little waste.

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, the description fully specifies the return shape ({cik, fundName, ... holdings} with row fields), plus the behavioral constraints. An agent has everything needed to call it correctly and interpret the result.

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 coverage is 100% (baseline 3), and the description still adds value on the fund parameter's resolution semantics (name-prefix match, resolved_from, ambiguous refusal) and on the returned row fields. It says nothing extra about max_holdings, but the schema covers it.

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+resource ('what one institutional filer owns ... latest SEC 13F-HR') with scope (largest positions plus QoQ changes) and filing form. An agent can distinguish it from siblings like get_institutional_holders, get_institutional_consensus, or ol_13f_filer_analytics.

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?

Gives explicit input routing (CIK preferred, ticker, or name) and an exclusion/fallback: an ambiguous name is refused with candidates and points to ol_13f_filer_search. It does not, however, state when to prefer this over get_institutional_holders or get_institutional_consensus.

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