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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description's value-add is the inventory of returned sections, which is real context but largely overlaps the existing output schema; no auth, rate-limit, or scoping caveats are disclosed.

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?

A single dense sentence that front-loads the primary output (fleet value and KPIs) and then enumerates secondary sections; the inflation_base note is placed last as a modifier. Long but every clause names a distinct returned artifact.

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 an output schema present, the description need not detail return values, and the two parameters are fully covered by the schema. It is complete enough for an agent to select and call the tool, missing only sibling routing guidance.

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 description coverage is 100%, so both parameters are already documented (portfolio_id 'From list_portfolios', inflation_base 'YYYY-MM'). The description restates inflation_base's effect (inflation-adjusted dollars) but adds no syntax or behavior beyond the schema, so the baseline 3 applies.

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?

Names a specific resource (one portfolio) and enumerates exactly what the tool returns: fleet value/KPIs, value history, segment/state split, forecast, newest events. Clear verb+resource, though it does not explicitly distinguish itself from siblings like get_portfolio_positions or get_portfolio_events that overlap on data.

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?

Usage is only implied by the word 'overview' — an agent can infer it is the aggregate/summary entry point, but nothing states when to prefer it over get_portfolio_positions, get_portfolio_positions, or get_portfolio_events. No prerequisites or exclusions are given.

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