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

Annotations already indicate readOnlyHint=true and openWorldHint=true. The description adds valuable behavioral context: hard-cached, WORM-sealed (immutable), and requires authentication. This goes beyond the annotations and helps the agent understand caching, data permanence, and auth requirements.

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 a single sentence that packs all essential information: purpose, data source, output fields, and key attributes (cached, sealed, auth). No filler words; every clause adds value. Front-loaded with the core purpose.

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 the tool's low complexity (1 parameter) and presence of an output schema, the description covers all necessary context: data source (Alpha Vantage), output fields, caching behavior, immutability (WORM-sealed), and authentication needs. It does not need to explain return values since an output schema exists.

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 100% with one parameter 'symbol' well-described in the schema. The description does not add further details about the parameter (e.g., accepted formats, case sensitivity) beyond the schema, so it meets the baseline for high coverage.

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 title 'Get a live market quote' and description clearly state the verb (get) and resource (live market quote). It lists specific data fields: price, change %, volume, day high/low, approximate spread, liquidity score. No sibling tool has a similar purpose, so differentiation is not needed.

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?

The description does not explicitly state when to use this tool versus alternatives. It implies use for market data but lacks explicit guidance on when not to use it (e.g., for historical data) or mention of alternative tools. The phrase 'hard-cached' hints at data freshness, but no clear usage context is provided.

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