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Skills

Short answer: A skill is a named bundle of related tools. Build Perch ships 25 built-in skills: 21 that carry tools, 3 that inject live workspace state into the prompt, and 1 reference the AI reads on demand. Each mode ships a handful of skills by default, and the AI can pull in any other skill mid-conversation when a task needs it.

What is a skill?

A skill groups related tools under one name: “Read & Search Files” bundles reading and searching across your workspace; “Templates” bundles the tools that fill Word/Excel/PowerPoint templates; and so on. Skills sit between individual tools and modes: a mode is really just a chosen set of skills plus a short instruction. Build Perch ships 25 built-in skills. 21 of them carry one or more tools (Read & Search Files, Edit & Organize Files, Power File Editing, Create Files, Templates, Cards, Conversation Memory, Workspace Memory, Media Editing, External Research, Images & Vision, Media Generation, Location, Ask Clarifying Questions, Skill Lookup, Agents, Workflows, Build Perch Help, plus the Email, Discord, and Notion integration skills). 3 more (Lists, Files, and Workers) don’t add any tool; instead they inject a live snapshot of your cards, file tree, or saved agents/workflows into the prompt at the start of each turn, saving the AI a discovery round-trip. The last one, Rich HTML Reference, carries neither tools nor a snapshot: it holds the reference sheet for the rich formatting chat replies can use (callouts, badges, card grids), and the AI reads it on demand instead of carrying the full text in every prompt.

How does the AI pull in a skill mid-turn?

A chat’s mode only ships a handful of skills by default, but the AI isn’t stuck with just those. When a task needs something else (say, an Assistant-mode chat where you suddenly ask for a PowerPoint deck), the model calls a built-in request_capability tool with the skill’s id and a one-line reason, and that skill’s tools become available on the very next round. This is capped at 5 skill pulls per turn. Once the AI has actually used a pulled-in skill’s tools, it stays available for the rest of that chat (up to 3 remembered skills at a time) so it doesn’t have to ask again; a skill it pulled in but hasn’t used yet is kept for one more turn (enough to ask you a clarifying question first) before it lapses.

Can I create my own skill?

Yes. The Modes & Skills editor lets you build a custom skill from any set of tools, give it a name and description, and include it in a custom mode. Built-in skills can be edited too, with a “Reset to default” option to undo changes; built-in skills can’t be deleted, but custom ones can.

Good to know

  • Toggling a skill on or off inside a chat relabels that chat “Custom” if it no longer matches its mode’s defaults; see Modes. Changing a chat’s settings (its limits, or a media-model pick) does not: only the tools a chat carries decide whether it reads as Custom.
  • File editing is split across two skills on purpose. Edit & Organize Files carries the everyday edits (text replace, Excel cells, Word paragraphs, PowerPoint slide text, plus move/delete/create-folder). Power File Editing carries the heavier structural work (Excel sheet add/rename/delete, row and column insert/delete, cell formatting and column widths; PowerPoint tables, speaker notes, and slide duplicate/delete/reorder). Writer mode bundles both; other modes carry the everyday one and pull the power skill in on demand, which keeps the tool list a smaller model has to reason over shorter.
  • The Email, Discord, and Notion skills self-suppress until you’ve connected that account under Integrations, so they don’t clutter the tool list before there’s anything for them to do.
  • Connecting the GitHub MCP server adds its own set of tools dynamically, separate from the 25 built-in skills; if a connected integration offers a richer equivalent of a built-in tool, the built-in one steps aside.