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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds substantial context: it is 'status-only', never returns rupee amounts, returns deterministic suggestions, and imposes presentation rules (grouping by confidence tier, exact counts, flagging medium/low rows, and avoiding the word 'pending'). This goes well beyond the annotations and clarifies the tool's behavioral safety and output expectations.

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, front-loaded with the primary purpose. The second sentence packs many required presentation rules, which is dense but each clause earns its place. It could be broken into bullet points for readability, but it is efficient and clear.

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?

No output schema exists, so the description takes on the burden of explaining return values: account names, types, target names, confidence, reasons, balance-bearing booleans, and the two completion counts. It also covers usage context. Gaps remain (e.g., ordering of results, definition of confidence tiers, pagination behavior) but the core information is present.

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%, with every parameter documented (e.g., client_id, page, page_size, name_patterns, unmapped_only, balance_bearing_only). The description does not add additional parameter-level meaning beyond what the schema already provides, and the baseline is 3 when the schema carries the burden.

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 starts with a specific verb+resource: 'Review account-to-cost-centre mapping status and deterministic suggestions'. It clearly distinguishes from sibling tools like confirm_centre_mappings or list_grouping_suggestions by emphasizing 'status-only' and listing exactly what is returned.

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 clearly sets the context: use this to review mapping status before confirming, and it explicitly states what data is NOT returned (no amounts). However, it does not name alternative tools or explicitly say when not to use it, so it stops short of a full 5.

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