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

Annotations already declare non-read-only, destructive, idempotent behavior, so the bar is lower. The description adds real context: invalid fields are rejected with guidance, null clears a field, and the call returns the full updated listing. It stops short of naming permission/auth requirements beyond 'a listing you own'.

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?

Front-loads the action, then the parameter format, then the constraints, then the return value, in four tight sentences with no filler. Every sentence carries distinct information.

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 no output schema, the description supplies the return contract ('full updated listing') and the failure mode (rejection of non-writable/computed fields with guidance). Nothing an agent needs to call this correctly 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%, so baseline is 3, but the description adds the registry-name convention (attr_* keys), a concrete example map, the enum/multiselect/null conventions, and the cross-reference to get_registry that the schema only restates. The added value is real but partially duplicative of the schema text.

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 precise verb+resource (set broker-authored attributes on a listing you own) and explicitly distinguishes itself from update_listing for hot columns and publish-time computed fields. An agent can route between this and update_listing without opening either 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?

Gives explicit prerequisites (field names must come from get_registry and be marked writable:true), an explicit exclusion (publish-time computed fields and hot columns -> use update_listing), and the selection rule for enum vs multiselect vs null. When-to-use and when-not-to-use are both covered.

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