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

Annotations already declare readOnlyHint=false, destructiveHint=true, idempotentHint=true, and openWorldHint=false, so the safety profile is covered. The description adds the genuinely useful authorization requirement (asset_replacement_plans:write scope), but it does not explain partial-update semantics, whether omitted fields are preserved or cleared, or what the 'destructive' aspect actually means in practice.

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 short sentences, front-loaded with the action and followed by the auth requirement; nothing is redundant or padded. It is appropriately sized for a straightforward update endpoint, though it could have used one more clause on update semantics without 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?

With annotations present and no output schema, the description is close to sufficient, but for a destructive, idempotent 8-parameter mutation it leaves a meaningful gap: whether the update is a partial patch or a full replace, and how the destructive hint manifests. It covers the scope requirement but not the mutation contract.

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 all 8 parameters documented, including enum values for status and priority, so the schema carries the parameter burden. The description only restates that the operation is keyed by ID, adding no format, constraint, or interpretation detail beyond the schema.

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 an existing asset replacement plan by ID'), which cleanly identifies the tool against its many update_* siblings. It does not explicitly name a sibling tool as an alternative, but the resource noun is specific enough that the agent can disambiguate without opening a 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?

There is no guidance on when to use this tool versus alternatives (create_asset_replacement_plan, bulk_update, or delete_asset_replacement_plan). The 'existing ... by ID' phrasing implies the record must already exist, but that is inference rather than stated guidance, and no exclusions or prerequisites beyond the scope string are given.

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