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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered. The description adds behavior the annotations do not: the month parameter defaults to the latest, and it discloses what the response contains (median, quartiles, >50% loss share).

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 sentences, no filler: the first defines the metric and its components, the second gives the usage context and the parameter default. Front-loaded and every clause earns its place.

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 no output schema, the description steps in to describe the return contents (median, quartiles, share of tokens losing more than half), and it covers the only parameter's default. An agent has everything needed to call and interpret it.

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% and the single param is already documented as optional YYYY-MM. The description still adds real meaning by stating the default-to-latest behavior, which the schema does not convey.

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 names the specific statistic and population: the median share of value lost selling a fixed $100,000 position across every token with a live on-chain market, plus quartiles and a tail share. That is far more than a restatement of the name, though it never explicitly distinguishes itself from the sibling exit_cost.

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?

It gives a clear use condition: 'Use for questions about overall crypto market liquidity or how hard it is to exit altcoins.' There is no explicit when-not or routing to exit_cost/other siblings, which keeps it short of a 5.

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