Set source configuration fields

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=true, so the write/gating profile is supplied structurally. Beyond that the description says nothing about whether the payload replaces or merges with existing configuration, whether credentials are stored or masked, or what permissions are needed — the crucial facts for a write tool that handles credentials.

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 the verb first and no filler or repetition. The density of internal jargon (ConfigurationPayload, adapter-instance) slightly reduces immediate comprehension but nothing is wasted.

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 two-parameter mutation tool with a nested, untyped payload and no output schema, the definition is thin: it neither explains payload structure nor points to a discovery tool (e.g. mpb_get_existing_object_type or mpb_list_collectors) nor says what a successful write returns. An agent can identify the tool but not confidently construct the call.

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 coverage is 50%: designId is documented in-schema with a pointer to mpb_list_designs, but payload is an opaque free-form object with additionalProperties and no schema description. The description partially compensates by naming the payload type and saying it holds configuration fields plus credential definitions, but it never explains the shape, required keys, or how to discover them.

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 gives a specific verb ('Writes') and a specific resource ('adapter-instance configuration fields and credential definitions'), and names the payload type (ConfigurationPayload). It does not, however, contrast itself with the closely named sibling mpb_set_source, so the agent must infer which one to reach for.

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?

The phrase 'users fill in when adding an account' hints at the lifecycle stage but gives no explicit when-to-use or when-not-to-use rule, and no alternative such as mpb_set_source or mpb_test_source is named. The agent has to guess the ordering and prerequisites on its own.

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