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

Annotations are all false and provide little behavioral information, so the description carries the burden. It usefully discloses that the tool 'automatically exchanges JWT tokens for a personal API key and activates it for the session,' revealing side effects beyond a simple login. This is meaningful transparency, though it stops short of explaining failure modes or key persistence details.

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 sentences with no filler. The core action is front-loaded, and the second sentence adds important behavioral context efficiently. Every phrase 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 two-parameter login tool with an output schema, the description covers the essential flow, side effect, and session activation. It is slightly incomplete in not offering usage direction against sibling authentication tools, but an agent can still invoke it correctly. The presence of an output schema means return values do not need to be described.

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%, and the schema already defines identifier as 'email address or username' and password as 'Account password.' The description mostly restates these meanings, adding no significant new semantic detail beyond confirming the login use case. Baseline 3 is appropriate because the schema does the heavy lifting.

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 clear, specific action: 'Sign in to Civify with email/username and password.' It also describes the unique post-login behavior (JWT exchange for a personal API key), which clearly distinguishes it from register, logout, and set_api_key siblings. There is no ambiguity about what the tool does.

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 context is implied: use this when a user has credentials and needs an authenticated session with a personal API key. However, it does not explicitly contrast with alternatives such as set_api_key for users who already have a key, or register for new accounts. The guidance is present but left mostly to inference.

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