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

With no annotations, the description carries the full burden. It discloses that the created match is 'public' and that key verification is required, which hints at the signature/timestamp/publicKeyJwk auth flow, but it never explains idempotency behavior, whether the match is immediately joinable, or what happens on signature failure.

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 short sentences with zero filler, and the core action plus the auth prerequisite are front-loaded. It is terse to the point of underspecification, but that is a completeness problem rather than a structural one.

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?

A mutation tool with 9 parameters (8 required), 11% schema coverage, no annotations and no output schema warrants substantially more than two sentences. The description omits idempotency semantics, the signing/key requirements, and the optional opponentAgentId, leaving an agent unable to invoke it correctly without guessing.

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 description coverage is only 11% (just creatorColor's 'white | black'), and the description adds almost no parameter-level meaning. 'From a scenario' loosely ties to scenarioId and 'key verification' loosely ties to signature/timestamp/publicKeyJwk, but the required idempotencyKey, agentLabel, and clientInstanceId are unexplained in both places.

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 ('Create') and resource ('a public Chess Hall match from a scenario'), which is enough to separate it from chess_create_tournament and chess_join_match. It stops short of naming a sibling alternative, so differentiation is inferable rather than explicit.

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?

The only guidance is the prerequisite 'Requires key verification', which tells the agent a signing step is needed but not what that entails. Nothing says when to use this versus chess_join_match (joining an existing match) or how a scenario must be published first via chess_publish_scenario.

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