investments_summary

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

With no annotations, the description carries the full behavioral burden. It discloses that the result covers a trailing window and specifically that BUY/SELL are excluded from cash figures because they are internal transfers. This is useful, non-obvious behavioral context. It omits other potential behaviors (e.g., output format, defaults), but for a summary read tool this is reasonable.

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 sentences, no filler. The core purpose is front-loaded, and the crucial exclusion is explained clearly in the second sentence. Every word earns its place.

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?

Although the tool is simple (one optional parameter, no output schema), the description fails to explain the months parameter at all, which is essential for correct invocation. It also does not describe the return format or whether there are any edge cases. The description is insufficient for an agent to use the tool correctly without guessing.

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?

The only parameter, months, receives zero explanation in the description. The schema provides only a type of integer with no description, so an agent has no idea what 'months' does (period length? trailing window duration?). The description does not compensate for this 0% schema coverage, leaving the tool ambiguous to invoke.

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 what the tool reports: portfolio value and cash inflows/outflows over a trailing window. It also clarifies the exact scope by excluding BUY/SELL from cash figures. This is a specific and meaningful purpose, but it does not explicitly differentiate from sibling tools like investments_balances or investments_transactions, so it misses the top score.

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 implies when to use the tool (to see net cash movement and portfolio value) and explains a key exclusion (BUY/SELL). However, it gives no explicit guidance on when to prefer this over the many sibling investment tools, nor does it mention any conditions or alternatives. Usage is left to inference.

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