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

Annotations already cover safety (readOnly, idempotent, non-destructive), and the description adds substantial extra context: append-only history, corrections modeled as newer reviews, the four disposition values, that owners/reviewers are intentionally not served, and the not_found scoping rule. This is real behavior an agent cannot infer from annotations.

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 front-loaded paragraph that leads with the resource and ordering before constraints and parameters; dense but every clause carries information. Slightly overlong sentences keep it from a 5.

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 enumerates the returned fields (disposition, note, next review date, recorded time) and the total-count behavior, and covers scoping errors and the id-type gotcha. Nothing needed to invoke it correctly is missing.

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 100%, so baseline is 3, but the description reinforces the exposure_id semantics (portfolio_book row id, not node_id) and confirms paging via limit/offset with the exact total in the response, adding meaning beyond the schema text.

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+resource ('credit review history' of 'one exposure') and a return ordering ('newest first'), which clearly separates it from siblings like portfolio_book and portfolio_reviews_due. An agent can identify exactly what it retrieves without opening the 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?

Gives clear context: it takes an exposure_id that is a portfolio_book row id (not a node_id), and an exposure outside the caller's team book returns not_found. It does not, however, name an alternative tool or spell out when to prefer a reviews-due listing over per-exposure history.

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