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

Description discloses that the credential is injected server-side and that any Authorization/auth header the caller sets will be ignored and replaced. It also explains that brokered credentials work even though they can never be revealed, which is important non-obvious behavior.

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?

The description is well-structured and front-loaded with the core action, but some later sentences restate the same idea (e.g., 'use it, you cannot see it' echoes the earlier 'without ever seeing plaintext'). Still, the extra guidance about allowlists and brokered credentials is valuable.

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?

The description provides enough context to choose and call the tool correctly, including constraints and side effects. It does not detail the response format, but an output schema is indicated and the description says the tool returns the upstream response, which is sufficient.

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?

All parameters are described in the schema with meaningful detail: id identifies the credential, url must be HTTPS and on the allowlist, method has an enum, body is raw and self-encoded, headers are extra and auth headers are ignored, and agentId is optional for agent-bound credentials.

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?

Clearly states the tool makes an outbound HTTPS call with a server-side attached credential and returns the upstream response. This strongly distinguishes it from read-only vault tools like vault_credential_get or vault_credential_get_totp.

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?

Explicitly tells when to use it: to act with a secret by calling an API or authed endpoint without seeing the plaintext. It also gives crucial constraints (target host must be on the credential allowlist) and explicitly prefers this over trying to read a secret.

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