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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds useful content-level context (methodology, limits, source links, fictional examples, no user records) and an output action (cite the canonical URL), exceeding the annotation bar without detailing pagination or error behavior.

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?

One dense sentence plus one short imperative; every clause earns its place, with the search-derived ID and the 'no user records' caveat front-loaded.

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?

Covers provenance of the ID, payload contents, and required citation behavior, and an output schema exists so return values need not be described. Minor gap: no error behavior for a stale or unknown ID, and no explicit sibling routing.

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?

There is only one parameter, and schema coverage is 0%, but the description supplies its origin: the ID returned by search. The enum itself ('proof') is self-documenting in the schema. Baseline is 3 for a lightweight, fully required single-param tool.

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 (Retrieve) and resource (public tool reference) with a distinguishing constraint: it works off the ID returned from search, which cleanly separates it from the search sibling. The name 'fetch' is generic, but the description carries the meaning.

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?

Explicitly ties usage to a prerequisite ('the ID returned from search'), routing the agent through the sibling first. It does not name plan_zkml_costs or state when-not-to-use, so it stops short of the top score.

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