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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context beyond annotations: the exact return shape (a nested object with hatch details), the optionality of workspaceId when paired, and the workspace-paired session prerequisite with an auth recovery path. This exceeds what annotations provide without contradicting them.

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 three sentences that pack the core purpose, return shape, three use cases, parameter optionality, and an auth prerequisite without fluff. It is front-loaded with the action and return value, and the less-common auth edge case appears last. Slightly dense but well-structured, so a 4 is warranted.

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 list tool with no output schema, the description fully covers the return type (including the nested object structure), the conditions for omitting workspaceId, and the session-pairing requirement. Nothing essential to invoking it correctly is missing; the auth flow is referenced and delegated to sibling tools appropriately.

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 schema already documents both parameters well. The description's note that 'workspaceId is optional when this connector is already paired' essentially echoes the schema's guidance ('Omit when the session is already scoped to a workspace'), adding little new meaning. Thus the baseline of 3 is appropriate.

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 ('List every hatch') and the resource ('in a workspace'), and it distinguishes itself from sibling tools like 'hatch' and 'lookup' by naming concrete use cases: when hatchIds are lost, before hatching to avoid duplicates, or when the user wants to know what is live. This makes the tool's purpose unmistakable.

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 lists when to use the tool ('when you lost hatchIds', 'before hatching', 'when the user asks what is live'), and it provides an alternative path ('call whoami, then get_pairing_code') for unpaired sessions. This gives the agent clear decision criteria and actionable fallback, satisfying the 'when/when-not/alternatives' criterion.

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