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

With no annotations, the description carries the full behavioral burden. It usefully discloses the bounded result set (max 500) and exposes a 'stale' field hinting at freshness semantics, but says nothing about side effects, permissions, or whether the call is purely read-only.

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?

Purpose is front-loaded in one sentence, parameters are grouped in a compact indented block, and the sibling pointer closes it out. No filler sentences; every line carries information an agent needs.

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?

No output schema exists, but the fields parameter's default list (score, grade, confidence, stale, computed_at) effectively documents the return shape, and all three params are covered. Only auth/permission expectations and the meaning of the SII acronym are left unstated.

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 0%, so the description must compensate and it does: it documents all three params with defaults, the sort_by enum values, the limit ceiling of 500, and the default field list including the special 'categories' value. This is materially more than the bare schema provides.

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+resource with scope and scale: 'Current SII scores (0-100) for scored stablecoins'. The word 'Current' implicitly separates it from the score_history sibling, and it names entity_read as the per-coin alternative, though it never explicitly contrasts with basis_answer or score_history.

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?

'Use before any decision involving stablecoins' gives a clear trigger condition, and 'One coin's detail: entity_read(query)' routes the agent to the alternative when a single-coin lookup is needed. No explicit when-not is stated, but the usage context is unambiguous.

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