Count datastores

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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds meaningful behavioral detail about dual execution paths depending on basic-auth configuration, which is not in annotations. This contextualizes how the count is obtained without contradicting any metadata.

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?

Two crisp sentences: the first states the core function and scope, the second explains implementation variability. No fluff, and the purpose is front-loaded. Every word earns its place.

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 count tool with no output schema, the description is nearly complete. It clarifies what is counted and how the count is derived. The only minor gap is an explicit statement of the return type (a number), but 'total number' strongly implies it, so this is acceptable.

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 has zero parameters and schema coverage is trivially 100%. Per the rubric, a baseline of 4 applies when there are no parameters. The description does not need to explain parameters, and it adds no irrelevant parameter information.

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 tool counts datastores (database clusters) across all CCX users. The verb 'count' and resource 'datastores' are unambiguous, and the global scope differentiates it from sibling tools like ccx_admin_list_datastores and ccx_admin_count_users.

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 the tool is for obtaining a total count rather than details, which separates it from list/get siblings. However, it does not explicitly state when to use it over alternatives (e.g., 'use this instead of listing datastores when you only need the number'). The context is clear but not exhaustive.

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