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

No annotations are provided, so the description carries the full burden. It discloses important side-effect boundaries: 'Moves no money and provisions no wallet by itself' and 'create or resume' implies persistence of identity. It also advises to reuse the returned userId, reducing redundant calls. It does not, however, detail what exactly 'create' entails (e.g., whether it writes to persistent storage) or any auth requirements.

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 sentences with no filler: purpose, call order, and side-effect exclusions are front-loaded. Every sentence adds value and the structure flows logically from 'what' to 'how/when'.

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 only 2 optional parameters and no output schema, the description fully covers what an agent needs: how to start (create/resume), when to call (first in loop), and how to use the result (reuse userId). It even clarifies non-effects (no money, no wallet). There is no missing critical detail for successful invocation.

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 property descriptions are sparse (only userId has one) and coverage is 50%. The description explains the meaning and reuse of userId ('reuse the returned userId on every other tool') but does not clarify displayName's purpose or expected format. Since the schema alone doesn't document displayName, this is a gap the description fails to fill.

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 states a specific verb and resource: 'Create or resume a human/org identity (userId)' and positions it as 'the first call in the loop'. It also distinguishes itself from siblings by noting 'Moves no money and provisions no wallet by itself', which differentiates it from money/wallet tools in the sibling list.

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 gives explicit when-to-use guidance: 'the first call in the loop' and 'call once and reuse the returned userId on every other tool'. It also implies not to use it for money or wallet operations, saying it 'moves no money and provisions no wallet by itself'. This is clear and actionable.

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