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

Annotations already declare readOnly/idempotent/openWorld/non-destructive, yet the description adds substantial behavior beyond them: proofs are re-verified locally from the pinned root key, live=true performs an initialize + tools/list against public addresses only, that live result is explicitly NOT signed, and history reflects only what LEGION observed. It also warns that a change is not a fault.

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?

Front-loaded with the core action and the read-only guarantee in the first two short sentences, then a dense but organized inventory of returned artifacts. The enumeration is long, but with no output schema it earns its place as return-value documentation.

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?

No output schema exists, and the description compensates by enumerating what is returned (leaf index, dates, tools_sha256, change counts, inclusion proof, signed tree head, evidence bundle, live diff). For a 2-parameter, non-destructive read tool this is sufficiently complete; only the url parameter's accepted form is left unstated.

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 0%, so the description must carry the parameters. It explains live=true meaningfully (compare currently served tool list against the signed list) and its default-on behavior is visible in the schema, but the required url parameter is never described (format, accepted public addresses, registry expectations). Half the parameters are clarified, half are left implicit.

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+resource: checking an MCP server URL against LEGION's signed transparency log, and summarizes the returned evidence (leaf index, proof, tree head, evidence bundle). It is clearly not a generic lookup. However, it never distinguishes itself from its close sibling check_mcp_server, which an agent cannot disambiguate from this text alone.

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?

Usage is implied rather than stated: the tool is read-only and tied to the transparency log, and it names verify_evidence_bundle as the downstream consumer of the evidence bundle. There is no explicit 'use this when / use check_mcp_server instead' guidance, so an agent must infer routing between the two server-checking siblings.

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