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

Annotations already flag destructiveHint and idempotentHint, but the description adds material behavior: partial-send semantics ('only the fields you pass are sent') and the replace-not-merge danger of tag_ids, which is exactly the kind of footgun an agent needs. It stops short of mentioning permissions or error behavior.

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 tight sentences, front-loaded with the WRITE marker and effect, with the highest-risk caveat (tag_ids replacement) placed before the endpoint reference. No filler.

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 covering safety hints, 100% schema coverage and no output schema, the description supplies the missing operational context (partial update, tag replacement, no customer notification). Only auth/error expectations are absent, which is a minor 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 coverage is 100%, so the baseline is 3, and the description goes beyond it by explaining the replacement semantics of tag_ids and the read-first workflow needed to preserve existing tags. It adds no detail for status or subject, but those are already fully documented in 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?

Opens with an explicit WRITE label, a concrete verb (change) and the resource (ticket), then enumerates the mutable fields. An agent can distinguish it from edesk_get_ticket or edesk_reply_to_ticket without opening the 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 real prerequisite ('read the ticket first') for the tag_ids case and implicitly routes to edesk_get_ticket/edesk_list_tags via the referenced field names. It also clarifies scope versus reply_to_ticket ('Nothing is sent to the customer'), though it never states when-not to use this tool.

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