session_login

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

With no annotations provided, the description must carry the full disclosure burden. It mentions the prerequisite of the extension and Pro, but does not clarify side effects, such as whether retrieving credentials also creates a session, whether credentials are returned to caller, or why masterPassword might be needed. The word 'login' in the name suggests possible session mutation, but the description only says 'decrypt and retrieve'.

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 two short sentences with no fluff. The main action is front-loaded, and the requirement is stated directly. Every word earns its place.

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 tool with no annotations and no output schema, this description is incomplete. It does not explain the optional parameters, the relationship with session_store_login, the return value, or the exact effect of calling it with mastePassword. An agent would likely struggle to know whether additional inputs are needed or what will happen after invocation.

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?

Only half of the parameters are described in the schema, and the description does not compensate for the undocumented tabId and masterPassword fields. It repeats 'domain' context already present in the schema and adds no meaning for the other parameters, especially masterPassword, which is likely relevant to decryption.

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 uses a specific verb ('Decrypt and retrieve') with a specific resource ('stored credentials for a domain'), making the tool's core function immediately clear. It also naturally distinguishes itself from siblings like session_store_login, which handles storing rather than retrieving credentials.

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 description provides a prerequisite ('Requires the extension and Pro') but gives no guidance on when to choose this tool over alternatives, such as session_store_login or session_navigate. There is no explicit 'when to use' or 'when not to use' context.

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