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

Annotations already cover the read-only, non-destructive safety profile, but the description adds genuinely non-obvious behavior: one row per ticker with the latest-restated value, tickers lacking data listed separately, and the critical caveat that each company's own fiscal calendar governs year/period so peer rows may span different calendar months. The Period End warning is exactly the kind of context an agent cannot infer from annotations.

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-loads the core action and scope in the first clause, then layers return-shape and the fiscal-calendar caveat in descending priority. Every sentence carries distinct information with no 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?

With no output schema, the description carries the return-value burden and does so: it describes row granularity, the latest-restated semantics, missing-ticker handling, and the Period End column to inspect. Combined with the fiscal-calendar caveat, an agent has enough to call and interpret the tool 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?

Schema coverage is 100%, so the baseline is 3, but the description adds interpretation meaning: fiscalYear/fiscalPeriod are resolved against each company's own fiscal calendar (NVDA example), which changes how an agent should set and read those parameters. It stops short of adding per-parameter syntax beyond the schema.

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: compare one financial concept across several companies for the same fiscal period, and labels the use case (peer comparison). This clearly separates it from the single-company GetFinancialFact sibling by scope (several tickers vs one) without needing to open 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?

'Peer comparison' implies when the tool is appropriate, and the multiple-tickers framing suggests its context versus single-fact tools. However, it never explicitly names GetFinancialFact as the alternative or states when NOT to use this tool, leaving routing to inference.

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