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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering safety behavior. The description adds context about the payload (price, market state, etc.) but does not disclose edge behaviors such as parameter precedence or not-found handling, which is acceptable given the annotation coverage.

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?

Two concise sentences: the first states the tool's purpose and outputs, the second provides parameter instructions. No filler words or redundant information.

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 simple read-only tool with rich annotations and an output schema, the description is largely complete. However, it creates slight ambiguity by instructing to provide either parameter while the schema marks both as optional (required=0), leaving unclear whether calling with no parameters is valid.

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%, so the baseline is 3. The description goes beyond by explaining that either instrument_id or ticker can be provided, clarifying their mutually exclusive relationship and providing an example format. It does not explain what happens if both are given, slightly reducing completeness.

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 uses a specific verb 'Get' and identifies the resource as 'financial instrument' while listing the exact data returned (price, price changes, market state, 52-week range, earnings date). This clearly distinguishes it from sibling tools like get_price_history or get_technical_indicators.

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 phrase 'current information' implies a snapshot use case, but the description does not explicitly state when to use this tool over alternatives like get_price_history or get_key_levels. No exclusions or alternative tool names are mentioned, leaving the usage context implied rather than explicit.

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