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

Beyond the readOnlyHint annotation, it discloses the denominator semantics (reported long-equity value, explicitly NOT AUM), edge-case behavior (a single stored quarter yields no fabricated turnover rate), and a named failure mode (unreachable store REFUSED with DATA_UNAVAILABLE), plus the data source. This is rich behavioral context an agent needs.

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?

Dense and slightly heavy on capitalization, but front-loaded with the core purpose and every clause carries operational information (return shape, denominator, exclusions, edge cases, source). Little filler.

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?

Although there is no output schema, the description enumerates the return keys ({summary, fund, quarter, n_positions, reported_long_equity_value, analytics}) and covers the failure modes, so an agent has everything needed to call and interpret it.

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% and the schema already documents 'fund' as a CIK with an example, so baseline would be 3. The description adds real value on top: it warns the value must be numeric and that a ticker will not resolve, which affects how the agent should supply the parameter.

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 precise verb+resource: derives institutional-filer behavior (concentration, turnover, persistence) from 13F holdings for one filer. It clearly distinguishes itself from siblings by naming ol_13f_filer_search for CIK resolution and get_13f_holdings for position lists.

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?

Explicitly states the input precondition (numeric CIK; a ticker will not resolve here), the tool to use instead when you lack the CIK (ol_13f_filer_search), and the tool to use instead when you want raw positions (get_13f_holdings). Nothing is left to inference.

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