Retrieve a chess player's costliest confirmed blunders, including FEN, move played and best move, to identify recurring mistakes and focus practice.
The player's costliest confirmed blunders with FEN, move played and best move.
| Name | Required | Description | Default |
|---|---|---|---|
| n | No | ||
| last_n | No | ||
| username | Yes | ||
| time_class | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations and no output schema, so the description carries the full burden. It discloses the returned fields (FEN, played move, best move), which is useful, but says nothing about what 'costliest' means (eval swing? win-probability?), what 'confirmed' implies (engine depth?), or whether this requires prior analysis via analyze_games.
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?
A single tight sentence with the key fields front-loaded behind the resource qualifier. Underspecified rather than bloated, so only a small deduction for terseness that omits needed routing and parameter context.
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?
For a 4-parameter tool with zero schema coverage, no annotations, and no output schema, the description leaves out how blunders are ranked, how n and last_n interact, and what analysis state is assumed. It is not complete enough to invoke confidently 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 0% across 4 parameters, and the description compensates only weakly: 'the player's' hints at username, but n, last_n, and time_class receive no explanation anywhere. The critical distinction between n (count) and last_n (game window) is left entirely ambiguous.
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 resource with a clear qualifier: the player's costliest confirmed blunders, plus the returned fields (FEN, move played, best move). This distinguishes it reasonably well from report-style siblings like weakness_report, though it doesn't explicitly contrast with missed_opportunities.
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 on when to pick this over missed_opportunities, weakness_report, or sacrifice_candidates, all of which plausibly surface similar material. No prerequisites or exclusions are stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.