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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds that the result is keys (not values) and that shared memory doubles as team swarm state, but says nothing about ordering, empty-space behavior, or permission requirements.

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?

Minimal and front-loaded with zero wasted words. The cost is that it is a sentence fragment rather than a complete statement of action, which slightly reduces clarity despite the tight size.

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 one-parameter, read-only list tool with full schema coverage and rich annotations, the essentials are present, including what is returned (keys). No output schema exists, so a brief note on result shape or empty-space behavior would have made it complete.

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 coverage is 100% and the single 'space' parameter is fully documented as 'Space key, owner/name' in the schema. The description only restates that a space is involved without adding format or scoping detail, so baseline 3 applies.

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 fragment names a specific resource (keys in a space's shared memory), which tells an agent what it retrieves, and 'keys' distinguishes it from a value-fetching sibling like memory_get. It lacks an explicit verb and any direct sibling differentiation, so it stops short of a 5.

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 parenthetical '(teams use it as swarm state)' hints at a usage scenario, which is more than nothing. However, it never states when to call this instead of memory_get, memory_set, or list_spaces, and gives no exclusions or prerequisites.

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