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

Annotations already declare readOnlyHint=true, so the description does not need to state read-only behavior. It adds value by specifying that it provides correlation and valuation difference, which is behavioral context beyond the annotation. However, it does not disclose any additional limitations or edge cases.

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?

The description is a single concise sentence that immediately states the purpose and the key output (counterparts, correlation, valuation difference). It is front-loaded with the core functionality and contains no redundant words.

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 simple read-only tool with two parameters and no nested objects, the description adequately explains the output and the intended use case. It does not mention pagination or limits, but given the likely small response size for a peer set and the readOnlyHint annotation, the coverage is sufficient. Absence of an output schema is partially compensated by the description's mention of correlation and valuation difference.

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 100%, with both parameters having clear descriptions (symbol: 'Either side of the PL<->US mapping; server canonicalizes'; market: 'Optional peer market filter'). The description does not add further parameter-specific guidance beyond what the schema already provides, so a baseline 3 is appropriate.

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 what the tool does: it returns company counterparts on the other market with correlation and valuation difference, specifically for comparing GPW with the US market. This is a specific verb+resource+scope, and it distinguishes itself from other get_* tools by focusing on cross-market peer comparison.

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 description gives a clear use case ('do porównania GPW z USA'), but it does not explicitly state when to use this tool vs. alternatives or when not to use it. It implies usage for cross-market comparison but lacks exclusions or references to sibling tools.

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