setCredential

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

With no annotations provided, the description fully bears the burden. It discloses that the tool is a write operation that never accepts the secret, returns a browser handoff for secure entry, and is gated by credentials access grant. It explains the security design and error responses. No contradictions with missing annotations.

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?

Every sentence is necessary and contributes value. The description is front-loaded with the core purpose, then systematically covers security design, return value, access control, error handling, and usage guidance. No redundancy or wasted words.

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 is fully complete for the tool's complexity: it explains what the tool does, how to use it, the return format, access gating, error codes, and the recommended post-step. Despite no output schema, the return shape is explicitly given. No gaps remain for an agent to misuse it.

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 100%, but the description adds significant context: appPackage is described as "The app's package / bundle id (project_install_id)", and credentialType explains why only meta_dat exists ("the assistant runs on the Extentos managed gateway and there is no provider key to supply"). This enriches the schema definitions.

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 clearly states the verb "Start WRITE-WITHOUT-KNOWING entry" and the resource "Meta DAT build identity", distinguishing it from siblings like getCredentialStatus which confirms the credential. It emphasizes the unique design of not passing the secret.

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 guides when to use: "USE to wire up a project's API key from the agent loop without ever handling the secret." Provides clear exclusions: "DON'T pass a key value (there is no field for it) and DON'T ask the developer to paste a secret into the chat." Suggests follow-up with getCredentialStatus. Also explains error scenarios (403, 401).

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