Join a team via access code

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

Annotations already indicate mutating, idempotent, non-destructive behavior. The description adds context beyond annotations by stating the current authenticated user is the subject, that the access code comes from umami_create_team or umami_get_team, and by providing the return shape. It does not fully describe side effects, but the annotation coverage lowers the burden.

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 compact and well-structured: a clear purpose sentence, a differentiating sentence, an args section, and a returns section. No filler or redundancy; every sentence carries necessary information.

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 single-parameter tool with no output schema, the description is complete: it explains the required input, where to get it, the operation semantics, and the return value format. Low complexity plus existing annotations make this fully adequate for correct 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?

Schema description coverage is 100%, so the baseline is 3. The description adds value by specifying the access code's provenance ('from umami_create_team or umami_get_team'), which is not present in the schema's simple 'The team's access code.' This extra guidance helps the agent know where to obtain a valid code.

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 and resource: 'Join a team as the currently authenticated user, using its access code.' It clearly differentiates itself from umami_add_team_user by framing the action as the self-serve counterpart, so an agent can distinguish between joining for oneself versus adding another user.

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 explicitly states when to use this tool vs. the alternative: 'This is the self-serve counterpart to umami_add_team_user, which an existing team manager uses to add someone else directly.' This gives a clear direct/indirect distinction with no inference required.

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