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

Annotations already establish the safe read-only, idempotent, non-destructive profile, so the bar is lower. The description adds genuinely useful behavior beyond that: units are actual dollars not millions, shares are split-adjusted, foreign issuers are reported in USD, and requesting a period earlier than the data returns an explanatory result.

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 but front-loaded: the kinds and their scope come first, defaults and unit conventions last. Each clause carries substantive detail, though the long parenthetical example lists make it heavier than strictly necessary.

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 carries return-shape burden and does so reasonably: it covers units (actual dollars, split-adjusted, USD), the source of definitions, defaults, and out-of-range period behavior. It stops short of describing the record structure or how kinds are keyed in the response.

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 the schema already documents ticker, kind and period including the enum and accepted period formats. The description restates defaults ('all', latest record) but adds no param syntax or meaning the schema lacks; the dollar/share/FX notes are output semantics rather than parameter guidance.

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 resource (company-reported measures outside GAAP statements) and enumerates the four kinds it returns (operating, non_gaap, bank, insurance) with concrete examples. The phrase 'outside its GAAP statements' cleanly separates it from get_financials/get_statements, so an agent can identify its scope without opening the schema.

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 clear default behavior ('every kind this company reports', 'every period in the latest record by default') and explains the data source (the company's own definitions from filings or earnings releases). It does not, however, name sibling alternatives such as get_key_figures, get_margins_and_ratios or get_financials, so the routing among metrics tools is left partly to inference.

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