get_identity

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

With no annotations provided, the description carries full burden. It discloses read-only safety, cross-project scope, the user fallback behavior, and the two-state response semantics ('not registered' vs 'lookup failed') with a recommendation to fail closed on the latter. This is rich behavioral context beyond what any annotation would provide.

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 compact but dense, with the core action front-loaded and every sentence contributing either scope, guidance, or behavioral semantics. No filler or repetition of schema fields.

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 no output schema, the description explains the return distinction and its implications for callers. It also covers cross-project behavior, relation to sibling tools, and edge cases (fallback, fail-closed). The tool is fully contextualized for an agent.

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 100%, so baseline is 3. The description adds relational context beyond the schema: the user param's fallback is explicitly tied to upsert_identity, and identity_name is identified as the same value used in SessionState.author / upsert_identity. This helps disambiguation and compensates for missing cross-references in the schema.

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 uses a specific verb ('Look up') and resource ('ONE identity record by name') and specifies scope ('cross-project, read-only'). It clearly distinguishes itself from the sibling tool list_context_authors, stating what get_identity does that the sibling cannot.

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?

Explicitly states when to use this tool ('when you need a specific actor's allowed_roles / independence_class') and names the alternative to avoid (list_context_authors), with a concrete reason why the alternative is inadequate. This is strong when-to-use guidance.

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