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

Annotations already declare readOnly/idempotent/non-destructive, so the description's added value is the display-only semantics, the auth requirement (api:read), and the fact that the response includes app_url for the Daily Moves screen. That goes beyond what the structured fields convey.

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?

One dense paragraph, front-loaded with the resource and usage, with no repeated filler. Slightly long but every clause (source tool, format, display-only caveat, auth) carries 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?

With no output schema, the description helpfully notes the response carries app_url, and it covers inputs, auth, and the non-actionable nature of the output. Enough for an agent to call it correctly and interpret the result.

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 only 50% (session_date has a pattern but no description), and the description compensates by spelling out the YYYY-MM-DD format and tying both parameters to their source in get_daily_moves.

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 ('example trade plan for one Daily Move') and explicitly scopes it as the per-item companion to get_daily_moves, so the agent can distinguish it from the sibling list tool without opening either 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?

Tells the agent exactly how to source inputs ('pass its security_id and session_date ... from get_daily_moves') and sets a clear exclusion ('never an order or a recommendation to trade'). It doesn't name the tool to use for actual trade proposals, but the usage context is unambiguous.

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