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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. Beyond that the description adds the sort order (last changed first) and the meaning of the status values (draft, exported, posted) plus what open_url represents, which annotations do not convey. It stops short of saying anything about volume, paging, or whether finished length can be null for drafts.

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?

Three short sentences, front-loaded with the resource and ordering, then the field set, then the sibling routing. The parenthetical status enum and the "where the person opens it" gloss on open_url earn their space by removing ambiguity; nothing is redundant.

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?

An output schema exists, so the description need not re-explain return values, and for a zero-parameter read-only list tool this is close to complete. The only real gap is the absence of any statement about result volume or pagination, which matters for an unbounded "all edits" listing.

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?

The tool takes no parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The description correctly avoids inventing filtering options that do not exist.

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 account's video edits in the Postkey editor, last changed first" names a specific verb-derived resource (a listing), the ordering, and the exact fields returned. It also defines the domain term ("An edit is the cut list of their own clips") and distinguishes itself from postkey_get_edit (single) and postkey_start_edit (create), so an agent can separate it from nearby siblings like postkey_list_edit_templates 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?

The description routes clearly: read one with postkey_get_edit, make a new one with postkey_start_edit, implying this tool is the enumeration path. It does not state exclusions such as when to prefer postkey_list_edit_templates or what to do if the list is long (paging), but the primary alternatives are named explicitly.

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