list_spaces

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 fully covered structurally. The description's only added behavioral signal is 'visible', implying results are filtered by the caller's access permissions rather than returning every space. It says nothing about pagination, ordering, or result volume.

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?

A single short, front-loaded sentence with no filler. It is appropriately sized for a parameterless list tool, though it is arguably too terse to convey context about what a space is.

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 zero-parameter read-only list, the description is close to sufficient, but in a 26-tool set with search_knowledge and list_documents it gives no indication of how spaces relate to documents or why an agent would enumerate them first. A sentence on the space/document hierarchy would close the gap.

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?

The tool takes zero parameters, so the baseline of 4 applies; there is nothing in the schema that the description could add meaning to.

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?

States a specific verb ('List') and resource ('knowledge spaces'), with a scope qualifier ('visible') that hints at access-scoped results. It does not explicitly contrast with siblings, but no sibling shares the 'space' resource, so the agent can distinguish it readily. The nature of a 'space' itself is left undefined.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives such as search_knowledge or list_documents that operate on content within spaces. The usage is only weakly implied by the name.

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