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

Annotations already cover the read-only, idempotent, non-destructive, closed-world profile, so the bar is lower. The description still adds real value by clarifying that the token conveys "only continuity of control" — i.e. it is not a broader authorization grant — which is a semantic subtlety an agent could otherwise get wrong. It stops short of describing failure behavior for an invalid token.

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 short sentences, purpose first, behavioral caveat second — no filler. Slightly more precision about the "self" scope would have earned the tighter, but nothing here is wasted.

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?

An output schema exists, so return values need not be described. However, for a tool whose main ambiguity is its difference from identity_get, and with 0% schema description coverage on both required params, the definition leaves the agent with unresolved questions before calling it.

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 0%, so the description must carry the load. It partially compensates by characterizing control_token as a private continuity-of-control credential, but identity_id is left completely unelaborated, leaving one of two required parameters with no semantics beyond its name.

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 gives a clear verb and resource ("Read a Garden identity") and names the credential required, but it never explains what "self" means here or how this differs from the sibling identity_get, which by name appears to do the same thing. An agent cannot reliably pick between the two from this text alone.

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 explicit when-to-use or when-not-to-use guidance, and no mention of the closest alternative identity_get. The only implied usage cue is the control-token prerequisite, which the agent must infer.

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