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

Annotations already indicate it's a write operation (readOnlyHint=false, destructiveHint=false), so the safety profile is known. The description adds valuable context about required API key, failure error format, and threshold logic beyond annotations, though it doesn't cover idempotency or side effects.

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 sentences, front-loaded with purpose and usage, then API key requirement, then error handling. Every sentence earns its place with no fluff.

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 complexity (9 parameters, write operation) and the presence of an output schema (which handles return values), the description covers purpose, usage, requirements, and error behavior adequately. Nothing critical 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%, so the schema documents all parameters. The description adds semantic relationships: explains that notify_on_drop/rise work without thresholds and that min/max_threshold_price are for target prices, and mentions the requirement of at least one. This adds meaning beyond the schema descriptions.

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?

States a specific verb and resource ('Create a price alert for a product') and explicitly distinguishes itself from update_price_alert and delete_price_alert by naming creation. An agent can identify the tool's purpose immediately.

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?

Provides clear context on when to use specific parameters and the mandatory constraint ('At least one of those four settings is required'), but does not explicitly route to sibling tools like update_price_alert for modifications.

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