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

With no annotations provided, the description carries the full burden. It mentions the free tier supports multiple addresses, adding some context about availability, but lacks details on permissions, rate limits, whether the claim is reversible, or what happens on failure. For a mutation tool with zero annotation coverage, this is insufficient.

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 concise sentences with zero waste, front-loaded with the core action and resource. Every sentence adds value: the first states the purpose, and the second provides tier context.

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?

Given one parameter with full schema coverage and no output schema, the description is adequate but incomplete. It covers the basic purpose and tier context but lacks behavioral details for a mutation tool, such as error handling or response format, leaving gaps in completeness.

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%, with the parameter 'address' fully documented in the schema. The description doesn't add any parameter-specific details beyond what the schema provides, such as validation rules or examples, so it meets the baseline of 3.

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 action ('Claim') and resource ('@agentlair.dev email address'), specifying it's for the user's agent. However, it doesn't explicitly differentiate from sibling tools like 'list_addresses' or 'check_inbox', which handle existing addresses rather than creating new ones.

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 implies usage by mentioning the 'Free tier supports multiple addresses,' suggesting it can be used when needing a new address. However, it doesn't provide explicit guidance on when to use this versus alternatives like 'list_addresses' for viewing existing ones or prerequisites for claiming.

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