list_namespaces

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

Annotations already mark readOnlyHint=true, but the description adds context: "It is read-only and does not mutate GitLab data; missing resources, invalid identifiers, insufficient permission, and rate limits are returned as errors." This goes beyond the annotation by disclosing error behavior. The mention of 'kind' that isn't in the schema slightly undermines confidence, but no contradiction with annotations exists.

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 first two sentences are effective, but the latter half includes generic boilerplate like "When `project_id` or `group_id` is accepted..." and "use required identifiers and pagination fields exactly as documented" — which are irrelevant to this schema and add noise. The message could be delivered in two tight sentences.

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?

No output schema exists, so the description carries the return-value burden. It does disclose read-only behavior and error conditions, which is helpful. However, it introduces nonexistent parameters (kind, project_id, group_id) and fails to explain pagination behavior beyond a generic directive. For a simple list tool, it is mostly comprehensive but contains enough mismatched guidance to lower 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%, so the baseline is 3. The description doesn't meaningfully expand on page, owned, search, or per_page; instead, it mentions filtering by 'kind' and IDs (project_id/group_id) that do not appear in the schema, adding potential confusion rather than semantic value.

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 and resource: "List all namespaces (users and groups) available to the current user." It also differentiates from sibling get tools by framing this as a collection-level listing, so the agent can distinguish it from get_namespace without opening the schema.

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?

Explicitly says when to use: "Use this for a collection of resources; choose the corresponding get tool when you already know the single resource to inspect." It also gives a filtering hint for groups only, which helps select the right call behavior.

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