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

With no annotations, the description carries the full burden. It discloses key behavior: requires a browser session, returns a redirect with a one-time code, uses PKCE S256, and binds the token to the MCP endpoint via the resource parameter. It lacks error-case or permission details, but covers the essential operational context.

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?

Four short sentences, each front-loaded with purpose, return behavior, requirement, and resource binding. No wasted words; the structure is efficient and easy to parse.

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 covers the tool's core purpose, return format, and auth requirement, which is useful given no output schema. But with 9 parameters and 0% schema coverage, it omits enough parameter detail that an agent must infer several inputs, leaving a completeness gap.

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 9 parameters. The description only explains `resource` (RFC 8707) and implicitly clarifies `code_challenge_method` (S256). It leaves parameters like `client_id`, `redirect_uri`, `state`, `scope`, `shop_id`, and `response_type` undocumented in both schema and description.

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 action: 'A signed-in person approves an agent client' and clarifies the output ('Returns the redirect with a one-time code'). It distinguishes itself from a token endpoint by focusing on the authorization step, though it does not name sibling tools like auth_oauthToken or auth_oauthRegister.

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?

It gives a clear condition: 'Needs a browser session, not an agent token,' which is a strong usage constraint and exclusion. However, it does not explicitly mention when to use this versus related OAuth siblings (e.g., auth_oauthToken for token exchange).

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