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

Annotations already declare readOnlyHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds one real behavioral fact not in the structured data — results are ordered newest first — and signals that only 'locked' reports are returned, which is meaningful scoping.

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 tight fragment that front-loads the resource and the ordering constraint; nothing is wasted. It reads as a label rather than a full sentence, but that is appropriate here.

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?

An output schema exists, so the description need not enumerate return values, and the safety annotations cover mutation behavior. The main gap is the absence of any routing guidance relative to sibling report tools, but for a simple one-parameter read this is otherwise complete.

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?

Only one parameter and schema description coverage is 100%, so the schema already documents portfolio_id (including its source, list_portfolios). The description adds nothing about the parameter, so the baseline of 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?

States the specific resource — a portfolio's locked point-in-time reports — with clear scope ('newest first' plus the field set returned). This distinguishes it reasonably well from generic siblings like search_reports and get_report, though the listing verb itself is only implied by the name.

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?

There is no when-to-use guidance: nothing says to call this instead of search_reports or get_report, and no prerequisite or context (e.g., when a portfolio is locked) is given. The only hint is the required portfolio_id, which the agent must infer means 'use for a specific portfolio'.

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