add_snapshot

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

Without annotations, the description discloses external dependency (Finnhub) and the two-step process (sync then record). But it does not clarify idempotency, side effects on existing prices, or error conditions.

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 with two clear clauses, no redundancy, and front-loads the key action and prerequisite.

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 parameters, no output schema, and no annotations, the description adequately explains purpose and precondition. It could mention return value or error handling, but it is still fairly complete for a simple creation tool.

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?

With zero parameters, the description adds meaningful context by explaining that the tool uses today's date implicitly and involves syncing external prices, which goes beyond the empty schema.

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 clearly states the tool syncs latest prices from Finnhub and records a snapshot for today, which distinguishes it from sibling tools like add_balance, edit_snapshot, or show_snapshot.

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 explicitly says it is 'required before snapshot data is useful', providing clear context for when to use it. However, it does not mention alternatives or when not to use it.

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