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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the safety profile is covered. The description adds genuinely new context beyond the structured fields: it requires a master API key, an auth escalation the agent would not otherwise know about. It stops short of saying whether existing owners are replaced or how partial failures are handled.

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?

The functional content is two tightly written sentences, front-loaded with the action and followed by the prerequisite. The injected pricing block consumes more words than the actual description, though it is machine-generated boilerplate rather than authorial bloat.

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 the master API key requirement is a useful addition. However, for a destructive, non-idempotent bulk mutation, the description gives no indication of overwrite semantics or partial-success behavior, leaving a meaningful gap.

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 only two self-documenting parameters (owner_id, account_ids), so the schema carries the load. The description adds no syntax, format, or cardinality guidance beyond what the schema already states, making 3 the correct baseline.

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 states a specific verb and resource (update account owner) and adds the scope qualifier 'for multiple accounts', which distinguishes it from the single-record sibling patch_apollo_accounts_account_id. It does not, however, contrast itself against the other near-identical bulk siblings such as post_apollo_accounts_bulk_update or post_apollo_contacts_update_owners.

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?

There is no explicit when-to-use guidance, no named alternatives, and no exclusions. The 'multiple accounts' phrasing only weakly implies this is the batch variant; an agent must infer from the name which of several bulk-account tools applies.

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