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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the mutation risk is covered structurally. The description adds one piece of real context — that auth is supplied via profile references rather than raw secrets — but it never explains what a destructive update overwrites, whether omitted fields are cleared or preserved, or whether the change is reversible.

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?

A single front-loaded sentence with no filler; the verb and resource lead. It is efficient, though arguably under-sized for an 8-parameter destructive mutation.

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?

An output schema exists, so return values need no explanation, but for a destructive 8-parameter update with zero schema descriptions the description leaves the agent without field semantics, merge/replace behavior, or side-effect detail. It is too thin for this tool's complexity.

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% across 8 parameters, including nested maps (baseUrlByEnvironment, authProfileIdByEnvironment, llmProviderConfigIdByEnvironment) and an enum (runtimeKind). The description's phrase "auth-profile references" loosely gestures at two of them but says nothing about id, name, description, runtimeKind, or defaultHeaders, so it fails to compensate for the coverage gap.

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?

The description states a specific verb+resource ("Update an upstream connection") and the sibling verbs (create/get/list) make the operation unambiguous. However, it does not differentiate itself from connection_create beyond the verb, and the trailing phrase "using safe configuration and auth-profile references" is fuzzy rather than scoping.

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?

There is no guidance on when to use this tool versus connection_create, connection_get, or connection_list, and no statement of preconditions (e.g. the connection must already exist, or that this replaces rather than merges fields). The agent must infer all routing from the name alone.

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