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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds genuine context by implying only 'user items' accept field edits (title/category/guidance/critical), which is a real constraint. It says nothing about permissions, reversibility of state changes, or whether omitted fields are preserved.

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 action and the full list of editable surfaces, followed by the usage cue. Nearly every clause earns its place, with only mild redundancy in repeating 'set its state' and 'edit a user item's fields' after the opening 'Update one diligence item'.

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 return values need no explanation, and annotations cover safety. However, for a 10-parameter mutation with 0% schema documentation, the description should at minimum flag the required identifiers and the partial-update semantics; those gaps leave the agent under-informed before calling.

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 0% across 10 parameters, so the description must carry the load. It names most editable surfaces (state with its enum, notes, photo_keys, value_impact, and the user-item fields), but leaves report_id, item_id, critical, category, and guidance only obliquely covered, and never clarifies that report_id/item_id are required.

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 ('Update one diligence item') and enumerates what can be changed: state, notes/photo keys, value_impact, and user-item fields. It is clearly distinguishable from add_diligence_item and delete_diligence_item by the verb, though it never names a sibling to sharpen the boundary.

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 closing line 'Use this to tick items off as you verify them' gives an implied usage context, but there is no guidance on when to prefer add_diligence_comment (whose job overlaps with the notes field here) or when the item must be user-created before fields can be edited. Usage is implied rather than specified.

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