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

Beyond annotations, it discloses that the tool is create-only, cannot modify or delete existing filters, fails when the name is already used, and has a 20-saves-per-day rate limit. These details explain the non-idempotent and non-destructive behavior and give the agent the operational constraints needed before mutating saved state.

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?

Four short sentences are front-loaded with purpose, mutation scope, duplicate-name failure, and rate limit. No sentence is filler; each carries operational information for invocation.

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 two-parameter tool with a complex nested filter, the schema carries the field-level detail and the output schema covers returns, while the description covers persistence, visibility, duplicate failure, rate limit, and non-destructive scope. Nothing essential for correct invocation is missing.

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% and the filter object is exhaustively documented in the schema, including per-field constraints and the list_filter_fields hint. The description adds the name-uniqueness constraint but otherwise does not add parameter meaning beyond the structured fields.

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 opening sentence names the exact action and resource: saving a buy box as a new named filter in the user's RBSHome account, with the visible outcome that it appears on the RBSHome map. This clearly distinguishes it from siblings like filter_properties and list_saved_filters.

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 clearly scopes use to creating a new saved filter and explicitly rules out changing or deleting existing filters, and it warns that duplicate names fail. It does not explicitly point to list_saved_filters for checking existing names or filter_properties for previewing, so alternatives are only implied.

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