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

No annotations exist, so the description carries the burden. It does disclose a real behavioral trait that structured fields do not: the x402 pay-per-call pricing and the API-key alternative, plus auto-pay behavior for x402-capable clients. It omits anything about the cost/behavior of an unknown signal name, caching, or response shape, leaving meaningful gaps for a no-annotation tool.

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 purpose is front-loaded in a single tight sentence, and the bracketed access clause is clearly separated. The payment paragraph is somewhat verbose for what it conveys but is not wasted, given no annotations exist.

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 should say something about what "complete metadata" includes (fields, dimensions, labeling) and what happens for an unregistered name. That is left entirely unspecified, which for a lookup tool with no annotations is a real gap.

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%, but the schema's own text is only "Signal name", so the baseline is 3. The word "exact" is the one piece of added meaning: it tells the agent matching is exact rather than fuzzy or prefix-based.

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 and resource ("Get complete metadata for a ... signal") and the qualifier "exact registered signal name" distinguishes it from fuzzy-search siblings like search_signals and match_signals. It never names those siblings explicitly, so the differentiation is inferable rather than stated.

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?

"Exact registered signal name" implies this is a lookup-when-you-already-know-the-name tool, which is useful implied guidance against search_signals/list_signals. However, no alternative is named and no condition for when-not-to-use it is given.

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