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

Goes meaningfully beyond the annotations: it discloses partial-update semantics (omitted fields retain values), the validation boundary (credential must exist and match auth_kind but the provider is never contacted), and that the updated config is returned. It does not explain the destructiveHint=true behavior the annotations imply—that headers and secret_headers are replaced wholesale—nor any auth/permission requirements, so it is strong but incomplete.

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 compact sentences, front-loaded with the action, and the second sentence earns its place by flagging the validation caveat. No filler, though 'such as its credential and headers' is slightly redundant given the schema enumerates the fields.

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 an 11-parameter mutation with nested objects and no output schema, the description covers the update semantics, validation scope, and return value adequately. It leaves out the wholesale replacement of headers/secret_headers and any permission or idempotency context, which matters given destructiveHint=true.

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 100%, so the per-parameter meaning (base_url, auth_kind, auth_options, timeouts, secret_headers) is already documented in the schema. The description adds only the cross-cutting partial-update rule, not parameter-level syntax, so the baseline of 3 is appropriate.

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 and resource with scope: it updates a model provider config's connection settings (credential, headers) and returns the updated config. The verb cleanly separates it from model_providers_create/get/delete by name, but the description itself never names a sibling or draws an explicit boundary, so it stops short of a 5.

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 by the word 'Updates' plus the partial-update note ('omitted fields keep their values'). There is no explicit when-to-use guidance, no statement of required org permissions/setup, and no routing to alternatives such as model_providers_create or model_providers_get.

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