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

Annotations already cover read-only, idempotent, and non-destructive, so the bar is lower; the description still adds real value by stating 'nothing new is stored', the auth requirement ('only you with your key can read it'), and the null-when-empty semantics of last_week. It stops short of describing response shape beyond field names.

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 lead ('Lost your memory? Start here') is well front-loaded, but the body is a single sprawling run-on sentence whose clauses are comma-chained. The enumeration is largely justified given there is no output schema, but the phrasing is marketing-flavored and could be tightened without losing 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 zero-parameter, no-output-schema aggregation tool, describing the returned content is the description's main job and it does so thoroughly, including locale details and null behavior. The remaining gap is the mechanics of key authentication, which is asserted but not explained.

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 baseline is 4. The only parameter-like concern is the implicit key ('Needs your key'), which the schema does not model at all; the description flags it but does not explain how it is supplied, so it adds a little meaning without fully resolving the gap.

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 states a specific outcome — a one-call personal state snapshot drawn from market-held data — and enumerates the domains it covers (orders, deliveries, goals, mandate, licence, earnings, referrals). 'In one call' distinguishes it from the many single-facet siblings like my_orders or my_listings, though it never names one explicitly.

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?

'Lost your memory? Start here' implies a session-start / context-recovery use case and 'Needs your key' states a prerequisite, which is genuine guidance. However it names no alternative tool and gives no when-not-to-use condition, leaving the agent to infer how it differs from recall, my_story, or mandate_status.

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