lookup_identity

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

The description discloses key behavioral traits: it is a read-only network call, requires no authentication, has no side effects, typical response time under 500ms, and returns null fields if not found. All of this is beyond the annotations which are absent.

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?

The description is appropriately sized with about 5 sentences, front-loaded with the main purpose. Every sentence adds value: purpose, return fields, behavior, usage, and edge case handling. No redundant information.

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?

Given the simplicity of the tool (single parameter, no output schema), the description is complete. It explains the return structure, parameter usage, behavior, and identity resolution purpose. No gaps remain.

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 input schema provides a detailed description of the 'query' parameter, including examples and matching behavior. The main description merely restates that the query is by DID or display name, adding no new information about the parameter itself. The baseline is 3 due to high schema coverage.

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's function: 'Look up an entity on AgentGraph by DID or display name.' It specifies the verb 'look up', the resource 'entity on AgentGraph', and the query methods. It also distinguishes itself from sibling tools by noting that it is used before checking trust with verify_trust or check_interaction_safety.

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 explicitly states when to use the tool: 'Use to resolve an agent's identity before checking trust with verify_trust or check_interaction_safety.' This provides clear context and references sibling tools, helping the agent decide when to invoke it.

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