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

No annotation covers cost or payment, and the description supplies that fully: $0.05 per call, USDC on Solana via x402, the no-payment-then-retry challenge handshake, and the exact _meta key. This is exactly the kind of context annotations can't express. It doesn't describe the response payload or failure modes, keeping it below a 5.

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 tight sentences: capability first, then pricing and the retry protocol, then the HTTP equivalent. The payment handshake detail is essential given it is non-obvious and otherwise undiscoverable. Slightly dense with embedded nested quotes, but no wasted words.

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?

There is no output schema, so the description is the only place an agent could learn what "resolve" returns — a canonical entity, matched register, confidence, or nothing found. That omission matters for a cross-register resolver, and openWorldHint combined with readOnlyHint=false leaves the read/write character ambiguous.

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 description coverage is 100%, and each of the five identifier parameters documents its format and the 'provide exactly one' constraint in the schema itself. The description adds nothing about parameters, so baseline 3 applies.

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?

"Resolve a company across UK, FR and AU registers" gives a specific verb (resolve) plus resource (company) and jurisdictional scope, which distinguishes it from lookup-style siblings like companies_uk_search or companies_enrich_financials. It stops short of explicitly naming which sibling to use instead for adjacent tasks (search, profile, ownership).

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 explains the payment mechanics but never says when to choose this over companies_uk_search, companies_enrich_profile, or companies_uk_lei, nor what preconditions exist (e.g. one identifier required). An agent must infer selection from the name alone.

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