compare_tickers

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

With no annotations, the description carries the full burden, and it discloses a significant behavioral trait: results are limited to tickers already in the cache (all S&P 500 names), with missing tickers reported back rather than silently dropped. It does not mention auth needs or rate-limit behavior, so a small gap remains for a no-annotation 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?

The definition is short, front-loaded on purpose and usage, then parameters. The 'Faster than scanning one at a time' sentence is mildly redundant but reinforces the usage rationale rather than wasting space.

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?

An output schema exists, so return-value explanation is unnecessary. Given two parameters and no annotations, the description covers purpose, when-to-use, the cache limitation, the fallback to scan_ticker, and both parameter formats — nothing an agent needs to invoke it correctly 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 0%, yet the description fully compensates: it gives the comma-separated string format with an example ('AAPL, MSFT, NVDA'), a hard cap of 25, the unit and valid range for expiry_weeks (1-52 weeks), and notes it applies to every ticker. This is more meaning than the bare schema offers.

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?

The first sentence states a specific verb (compare) and resource (catalyst risk across several stocks) with a scoping constraint (same expiry window). It distinguishes itself from siblings like scan_ticker by operating on multiple tickers at once, which an agent can grasp 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?

It explicitly states when to use it ('choosing between tickers to sell options on', 'which of several stocks is the safest bet') and names the alternative for the single-ticker case (scan_ticker). Both the selection condition and the fallback path are spelled out.

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