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

With no annotations, the description carries full transparency burden and succeeds. It discloses the critical ambiguity that several crypto symbols are also US-listed equity tickers, warns that a bare ticker returns the equity, and instructs the agent to 'Check is_stale before using the price'. These are substantial behavioral details not present in the schema.

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 description is front-loaded with the core purpose and then flows into usage triggers, history alternative, crypto handling, and staleness check. Every sentence earns its place with high signal and no repetition or 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?

Given no annotations and no output schema, this description is complete: it explains what the tool returns, when to use it, which alternative covers history, how to avoid the crypto/equity trap, and what to check before trusting the price. An agent has everything needed to select and invoke it 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 description coverage is 0%, but the description compensates exceptionally. It explains the asset_class parameter with examples ('pass asset_class=crypto for BTC/ETH/SOL/LTC/LINK'), and clarifies the default equity behavior of bare tickers, adding crucial meaning to both ticker and asset_class beyond the raw enum/default.

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 description opens with 'Latest quote for one ticker — last trade plus the current daily bar', which clearly identifies the resource (one ticker), the action (quote), and the return content. It also distinguishes itself from history-related siblings by explicitly sending those requests to /fundamentals/prices.

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 provides direct usage triggers: 'Call this when the user asks what the price is now or how the stock is moving today' and names the alternative for history. It also includes crypto-specific instructions, telling the agent to pass asset_class=crypto and never use an equity price for a crypto asset.

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