my_identity

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds real behavioral content by clarifying that no identity is created and that the returned values are immutable, which reassures an agent it cannot mutate state here. It does not say what happens if no identity exists yet or whether the result is cached/stable across calls.

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, front-loaded with what is returned before the disambiguating clause. Nothing is redundant or padded.

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?

With no output schema, the description carries the burden of describing return values and does so by listing the four fields obtained. For a zero-parameter read tool this is nearly sufficient; only the behavior when no identity exists is left unstated.

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 no parameter semantics to document. The description correctly implies a no-argument call by describing an implicitly-scoped 'your' identity.

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 concrete resource (the caller's own identity) and enumerates what it returns: immutable UUID, public CN ID, handle and current limits. 'No new identity is created' explicitly separates it from register_agent, a sibling present in the list. The verb 'verify and retain' is less crisp than 'get', but the scope is unambiguous.

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 exclusion ('No new identity is created') implies that registration is a different tool, which nudges an agent toward register_agent instead of this one. However, it never names that alternative or states when this tool should be called (e.g. at session start, after registration, to check limits). Guidance is implied rather than explicit.

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