Who am I and which companies can I reach

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

Even with readOnlyHint and destructiveHint annotations, the description adds valuable context: it reports the active tenant and the server's write policy, and clarifies that the tenant list includes id, slug, and currency. This goes beyond the annotations and sets accurate expectations.

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 two sentences long, front-loaded with the core purpose, and the second sentence provides crucial usage context. Every phrase earns its place without redundancy or fluff.

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?

Despite lacking an output schema, the description fully conveys what the tool returns (user identity, tenant list with fields, active tenant, write policy). It also provides essential session context, making it complete for a zero-parameter tool in this sibling set.

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 has zero parameters and an empty schema, so the description carries no parameter burden. It appropriately describes the tool's role without needing to explain inputs, meeting the baseline for parameterless tools.

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 specific verbs ('Identify' and 'list') and clearly states the resource (the authenticated ReAI user and every accessible tenant). It distinguishes itself from siblings by focusing on session initialization and tenant discovery, which no other sibling tool does.

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 says 'Call this first in any session' and explains why: most other tools are tenant-scoped and require the tenant id. This provides clear when-to-use guidance and effectively positions it relative to tenant-scoped siblings.

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