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 tool uses real Stockfish 10 (asm.js), is single-threaded, and runs in-isolate per call. It also mentions no mocks. However, it does not cover potential errors, rate limits, or authorization needs.

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 efficient sentences. The first sentence front-loads the core purpose and outputs. The second adds crucial behavioral context. Every word 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?

While the description mentions return values (best move, score, variation), it lacks details on output structure. With no output schema, this is a gap. Parameter explanations are minimal. The tool has 3 parameters and 1 required, but only multipv is mentioned. Overall, it is adequate but not comprehensive.

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 explain parameter meanings. It only mentions 'optional multipv' but does not explain 'fen' or 'depth'. The outputs described (best move, score) are not parameter-related. This leaves significant gaps in understanding how to use the parameters.

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 clearly states the tool evaluates a chess position with Stockfish and lists outputs (best move, centipawn/mate score, principal variation, multipv). However, it does not explicitly differentiate from the sibling tool 'best_line', leaving ambiguity about when to choose one over the other.

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?

No guidance is provided on when to use this tool versus the sibling 'best_line' or alternatives. It does not mention prerequisites, limitations, or when not to use the tool.

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