Search Jira Cloud issues with JQL. Returns items and an opaque next_page_token (null on the last page); pass it back as page_token for the next page. limit is 1..100 (default 20); 0 is invalid. fields replaces the default fields entirely -- default: summary, status, issuetype, priority, assignee, updated, project. fields=[] returns only the issue key.

Fetch one issue by key. fields replaces the default fields entirely -- default: summary, description, issuetype, status, priority, assignee, reporter, labels, components, created, updated, resolutiondate, issuelinks, project, parent, subtasks. fields=[] returns the key with no fields. Does not include comments, attachments, or changelog history; use the dedicated tools for those.

List an issue's comments. order='desc' (default) returns newest first; 'asc' returns oldest first. start_at/limit paginate the logical, filtered, sorted collection (ties broken by comment id); limit=0 returns every remaining comment from start_at with no 100-comment cap. since (ISO-8601 with an explicit offset) keeps only comments created at or after that instant, and total reflects the filtered collection.

List an issue's attachment metadata (id, filename, mime_type, size, author, created) without downloading content. Use download_attachment to fetch a file's bytes.

Download one attachment by id into a process-scoped temporary cache and return its local_path. The cache is removed when the server shuts down.

List an issue's field-change history. order='desc' (default) returns newest first; 'asc' returns oldest first. start_at/limit paginate the logical, sorted collection (ties broken by entry id); limit=0 returns every remaining entry from start_at with no cap. Each entry lists human-readable field changes.

Add one comment to an issue. body is Markdown -- headings, lists, fenced code blocks, bold/italic, inline code, links -- converted to Jira's rich text; anything outside that set stays literal. Returns the created comment in the same shape get_comments returns. This server cannot edit or delete a comment afterwards.

Move an issue through its workflow. to is a transition name or the name of the status to reach, matched ignoring case and surrounding space. A transition's name often differs from the status it leads to (a transition called 'In Progress' can produce status 'In Development'), and two transitions can reach one status, so prefer the transition name; if nothing matches, the error lists every available transition and its resulting status. comment is Markdown and is posted in the same call as the move. Changes issue state.

Set issue fields, taking the same values get_issue returns: summary as text, description as Markdown, assignee as an account id or the literal "me", labels as a list, components and priority by name, duedate as YYYY-MM-DD, parent as an issue key, and any customfield_* or unknown field as raw Jira JSON. null clears assignee, description, priority, parent, or duedate. labels and components REPLACE the whole list, so read the issue first if you mean to add one. Cannot change status (use transition_issue) or add a comment (use add_comment).