switch_active_model

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

Annotations already declare it is a write (readOnlyHint=false), non-idempotent, and non-destructive, so the safety profile is covered. The description adds real value beyond that: it discloses atomicity and the exact failure contract (ok:false / reason:'incomplete' when a chunk lacks a shadow embedding). It omits what happens to the previously active model and whether auth is needed.

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?

Two tight sentences, zero waste, with the core action front-loaded and the failure semantics immediately after. Every clause earns its place.

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?

For a mutation tool with no output schema and 0% parameter coverage, the description covers the success effect and failure mode reasonably but leaves the vault parameter and the post-switch state of the prior active model undocumented.

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?

Schema description coverage is 0%, so the description must carry the burden. It clarifies that model_name must be a *registered* model with shadow embeddings, but says nothing about 'vault' and adds no format, naming, or value detail for either parameter.

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?

States a specific verb+resource ('promote a registered model to active') with the added qualifier 'atomically', so the effect is unambiguous. It does not explicitly differentiate itself from siblings like list_models or start_shadow_index, but the action is distinct enough to select on.

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?

Usage is only implied: the mention of a required 'shadow embedding for the target model' hints at a precondition (shadow index must exist) but never states when to call this versus alternatives or what state must hold. No explicit when/when-not guidance.

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