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

Annotations declare destructiveHint=true and idempotentHint=true; the description adds the important batch semantics: all-or-nothing atomicity, the failure mode (NOTHING is changed and the error lists the offending ids), and the return payload. It could go further by stating explicitly that existing descriptions on those DIDs are overwritten, which is the destructive aspect, but the added context is substantial.

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 and scope, then the alternative, then the failure behavior, then the return value. Dense but every clause carries information; only minor tightening is possible.

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 2-param mutation with no output schema, the description supplies the atomicity contract, the error behavior, and the return shape (numbers with resulting description and count). Nothing an agent needs to call it safely 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 description coverage is 100%, so the schema already documents did_ids (UUIDs, 1..100, must belong to the customer) and description (free text, null/"" clears). The description restates the max-100 limit and the clearing semantics rather than adding new meaning, so the baseline 3 applies.

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 specific verb (Set/clear) and resource (the description of the customer's DIDs) with scope (one or more DIDs, max 100). It also explicitly contrasts itself with the sibling update_did, so an agent can route correctly 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?

Gives a concrete when-to-use ('label several numbers at once, e.g. all numbers of an order or a ticket') and names the alternative ('update_did does the same for a single DID together with its renewal'), plus the clearing trigger (null or "").

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