get_stock_quote

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered. The description adds genuinely non-derivable behavior: an unknown ticker or upstream/rate-limit failure returns a short error message instead of raising — important for agent error handling that no annotation conveys. It stops short of describing freshness/latency guarantees or pagination (not applicable here).

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?

Three short blocks, front-loaded with what it returns, then sibling routing, then output/error behavior. There is no filler and no repeated phrasing; the enumerated field list is dense rather than padded.

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 two-parameter read tool with a full schema and an output schema, the description covers selection guidance, output format choice, and failure semantics. 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 100%, with both ticker examples and the response_format enum fully documented, so the schema carries the load. The description only restates the output-format choice ('Markdown by default, or structured JSON when response_format=json'), adding little beyond the schema's own default and enum description.

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 names a specific verb and resource ('Real-time quote snapshot') and constrains scope to 'ONE stock', then enumerates the exact fields returned (price, day change, ranges, volume, market cap, beta, P/E, EPS, yield, sector). That field list lets an agent distinguish it from get_company_info or get_financial_statements without opening any 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 gives both a positive trigger ('what's the price of X' or a quick single-stock snapshot) and explicit routing to three named alternatives: compare_stocks for multiple stocks, get_company_info for the full profile, get_historical_prices for a past price series. The when-not-to-use conditions are stated rather than inferred.

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