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

Annotations already establish readOnlyHint=true and openWorldHint=false, so safety is covered. The description's contribution is the payload contents (id, name, plan, usage), which matters because there is no output schema, but it says nothing about failure modes such as an invalid or revoked key.

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 sentence with a front-loaded subject and a compact enumeration of returned fields. Nothing is redundant and nothing needs to be skimmed past.

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, no-output-schema tool, the returned-field listing is exactly the missing piece and it is supplied. Only the ambiguous overlap with get_usage's territory is left unaddressed.

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 there is nothing for the description to disambiguate. The baseline of 4 applies; no parameter-level ambiguity exists.

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 names a specific resource (the workspace tied to the calling key) and enumerates what it returns: id, name, plan, and current-period usage. That is far more concrete than the title. It stops short of differentiating from get_usage/get_project, which touch adjacent data.

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 phrase 'this key belongs to' implies the use case — resolving the authenticated workspace's identity — but there is no explicit when-to-use statement and no exclusion pointing to get_usage for a deeper usage breakdown or get_project for project scoping.

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