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

Annotations already declare destructiveHint=true, but the description adds meaningful context: 'Executes directly for the authenticated app owner' signals immediate execution without review, and 'expected_count aborts the write on a mismatch' explains a safety mechanism. These go beyond the annotations and help the agent understand side effects.

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 with no filler. The core action is front-loaded ('Update exact records'), followed by the selection modes and the key behavioral note. Every phrase 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?

For a destructive write tool with 8 parameters and nested objects, the description covers the essential decision points: how to select records, what changes to provide, and the safety check. It doesn't mention return values (no output schema) but that's acceptable; the missing piece is an explicit note about scope (e.g., only exact matches, no partial updates), though the phrase 'exact records' implies it.

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 all parameters are individually documented. The description adds conceptual value by explaining the two usage patterns (shared changes vs per-record updates) and the role of expected_count as a safety check, which clarifies how multiple parameters interact beyond their individual schema descriptions.

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 the tool updates exact records, and specifies two distinct modes: selecting record_ids or exact-match filters with shared changes, or providing per-record updates. This is specific and immediately distinguishes it from create/delete tools, and from the singular update_entity_record sibling.

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?

It implies usage through 'exact records' and the selection methods, but doesn't explicitly contrast with update_entity_record (singular) or update_entity_metadata. There is no 'when not to use' or note about choosing this over alternatives, leaving some inference to the agent.

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