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

Annotations only declare readOnlyHint=true, yet the description discloses substantial extra behavior: a 24h cache, a Researcher-tier auth requirement, an IFRS refusal path ('never served zeros'), and pre-split share-count withholding. It also warns that netBuybacks is a derived dilution proxy rather than a true buyback figure, which prevents a serious misreading.

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 purpose is front-loaded in the first clause, and every sentence carries load-bearing information (return shape, caveats, refusal behavior, source, cache, tier). It is dense and parenthetical-heavy, but no sentence is redundant, so it earns its length.

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 object and its parallel-array alignment, plus source, cache duration, tier requirement, and refusal/withholding edge cases. An agent has everything needed to call it and interpret results correctly.

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?

With a single parameter at 100% schema description coverage, the schema already documents ticker and the description adds nothing parameter-specific. The extra detail it provides (fiscal labels, newest-first ordering, parallel arrays) describes output shape, not parameter semantics, so the baseline 3 applies.

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 ('Where a company sent its cash') with a concrete scope ('up to 30 annual labels'), and explicitly names the complementary siblings get_fundamentals and get_debt_maturities. An agent can distinguish this from other fundamentals-family tools 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?

The phrase 'Complements get_fundamentals and get_debt_maturities' gives implied routing context, and the Researcher-tier requirement plus the IFRS refusal effectively constrain when it can be used. However, there is no explicit when-to-use-vs-alternative guidance or exclusion criteria, so usage is only implied.

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