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

Goes well beyond the readOnly/idempotent/openWorld annotations: it warns that valuation can be unavailable without quote configuration, that each section reports availability independently, that missing or stale values are flagged and never coerced to zero, and that source filing identifiers are returned. These are exactly the failure-mode and data-integrity traits an agent needs before calling a research tool.

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 one-line summary, then uses two tight bullets for the views, each ending with the caveat specific to that mode. Every sentence carries information; the closing 'Research summary, not financial advice' is a short, purposeful disclaimer.

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?

For a three-parameter tool with no output schema, the description covers what each view returns, availability caveats, and peer requirements well. Minor gaps remain around invalid or non-US tickers and whether results_review works on non-US filers, but nothing critical for correct invocation is missing.

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 67%, and the description fills the remaining gap by explaining what view=results_review actually produces, that peerTickers must be 1–5 period-aligned comparables, and the interaction rule of asking the user when peers are absent. It adds real semantic meaning over the enum and array constraints, though it says little about ticker format beyond the schema's 'US ticker symbol'.

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 ('One-call company overview') and then enumerates the two distinct views with the exact contents of each (TTM SEC financials, ratios, valuation, filings, insider transactions vs. XBRL results, peers, changed MD&A/Risk Factors passages). An agent can tell immediately what it gets and how the two modes differ.

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 contextual guidance for mode selection: 'snapshot' is the default overview, 'results_review' is for a review packet on the latest 10-Q/10-K, and it explicitly instructs the agent to ask the user for peer companies rather than guessing when peers are unnamed. It does not, however, route the agent toward or away from sibling tools such as build_research_report, so the comparative guidance is only internal to this tool.

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