3. The core invariant

The elements of every result must be valid inputs to every other function. Fully-qualified symbols are the universal currency; more precisely, every thing is identified by the value a Clojure reader would produce for it — symbols for namespaces and vars, keywords for keywords, strings for files. Never a wrapper map, never an opaque handle.

Consequences:

• Results stream self-describing elements, flat. Not {ns → [entries]} — that breaks mapcat at the first hop. Each entry carries its own :sym, :file, :row.
• :sym is a symbol, not :name/:ns strings. String pairs force reassembly at every hop; this is the most common way a library like this fails to compose.
• The container type is incidental. Eduction, lazy seq, vector — irrelevant. What matters is the element type. Pipelines land on into [], which is also what makes the result something shape will look at.
• Uniformity holds across functions, not just within one. Minimizing the number of distinct element types matters more than making each maximally informative. Two cover nearly everything:

;; entry — a top-level form
{:sym  'co.multiply.module.driver.impl/run-crawl-one
 :kind :defn :arglists '([ctx tool])
 :file "…/impl.clj" :row 412 :end-row 449 :doc "…"}

;; site — a reference to something
{:sym  'co.multiply.module.driver.impl/run-one   ; nil at top level
 :file "…/impl.clj" :row 517 :col 23 :top-level false}

function	streams
namespaces	ns symbols
outline, changed-forms	entry maps
form	entry maps + :source
usages, kw-usages	site maps
rename	edit maps
trace	node maps

No options where data will do. Every option is a sign the return value was not data-shaped enough:

• :context 1 (neighbouring forms) → outline returns an ordered vector; neighbour selection is clojure.core.
• :tail 50, regex, grep-context on stdout → out returns a vector of [ts thread line]; tail is take-last, grep is filter, context is partition.
• :full true on shape → see §6; the types already make the distinction.

No query DSL. Tools in this space reliably grow one — glob patterns, selector syntax, --filter flags. Transducers over plain data make it unnecessary. That is a large avoided cost.

Nothing in the library returns prose. form streams entries with :source attached; a separate small printer renders. Rendering lives at exactly one boundary per pipeline.

The one knob that survives is how much of a result crosses into the agent's context — not expressible as composition, because it is a property of the transport. It belongs to the eval tool, not to any function.