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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds that the payload reports freshness, size, and source-agreement, plus that generated_at should be quoted, but with no output schema it does not describe the stat structure or freshness semantics in depth.

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?

Two tight, front-loaded sentences: the first names the payload, the second gives the action directive. No filler, and the most important instruction ('Call first') is prominent.

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?

For a zero-param, zero-annotation-ambiguity status tool with no output schema, the description covers what stats come back and the key field to surface. It stops short of explaining what 'source-agreement' or 'freshness' numerically mean, a minor 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?

The tool takes zero parameters, so there is nothing for the description to document and the baseline of 4 applies. The absence of arguments is consistent with a parameterless status call.

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 resource and the data it returns: 'Freshness, size and source-agreement stats of the token universe.' An agent can tell this is a status/metadata tool distinct from retrieval siblings like tc_get_token or tc_list_tokens, though it doesn't explicitly name what sets it apart from tc_brief or tc_ledger.

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?

'Call first' is explicit sequencing guidance that tells the agent when to invoke this relative to other tools, and 'quote generated_at' directs downstream use of the output. There is no explicit when-not or named alternative, but the usage context is clear.

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