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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely new context: credentials are excluded from the returned profile and no authentication is required, which affects both trust and callability of the result.

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?

Three short sentences, front-loaded with the action and constraint; nothing is padded. Minor redundancy from stating 'Public' twice across the middle and final 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?

An output schema exists, so return shape need not be described, and the description correctly supplements it with the credentials-exclusion note and the no-auth requirement. The only real omission, ID format, is covered by the schema pattern.

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 0%, so the description must carry the load for the single agent_id parameter. It adds the useful semantic that the ID is an opaque identity handle, but omits the expected format (the agt_ + 32 hex pattern lives only in the schema), so it only partially compensates.

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 ('Retrieve a durable identity') scoped 'by opaque ID', which implicitly distinguishes it from get_current_agent and list_agents. It does not name those siblings explicitly, so the differentiation is inferred rather than stated.

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?

Provides a usable condition ('Public; no authentication required'), which tells the agent it can call this without credentials. However, it never states when to prefer this over get_current_agent (self) or list_agents, leaving the selection between the three profile-read tools to inference.

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