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

Annotations already declare destructiveHint=true, idempotentHint=true and openWorldHint=false, so the safety profile is covered structurally. The description earns credit for disclosing the permission requirement and, importantly, the partial-overwrite rule — an agent reading only destructiveHint=true might wrongly assume the whole record is replaced. It does not say whether the change is reversible or what an overwrite of a nonexistent field name does.

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?

Three short sentences, front-loaded with the operation and its key semantic, then the input convention, then the permission requirement. Every sentence carries information; the only cost is that the access requirement is placed last rather than flagged earlier.

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 four-parameter mutation tool with no output schema, the definition covers the operation, the partial-update behavior, the input convention and the auth requirement. Gaps remain around return value and failure modes (invalid field names, missing entity), but nothing essential to selecting or invoking the tool is absent.

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 50%: entityType carries its allowed values in the schema and data has a one-line description, while campaignId and entityId are bare strings. The description adds real meaning for data by pointing at get_entity as the source of valid field names, but contributes nothing about the two undocumented ID parameters.

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 names a specific verb and resource ('Overwrites the given fields of one entity') and immediately pins down the partial-update semantics ('fields left out are kept'), which separates it cleanly from create_entity and delete_entity in the sibling set. An agent can tell what this does 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?

It gives a concrete prerequisite workflow ('Use the field names get_entity returns') and an access condition ('Requires the Editor role'), which is more than most mutation tools offer. It stops short of saying when to prefer this over alternatives such as set_relationship or create_entity, so it is clear context without exclusions.

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