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

Annotations already readOnlyHint=true and openWorldHint=false. The description adds the cost (10 credits) and describes the return content (recent meetings, win/loss record, average margin), providing behavioral context beyond the annotations. No contradiction.

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?

Three concise sentences: purpose and outputs, filtering option, and cost. All information is front-loaded, with no wasted words or redundant details.

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 comparison tool with 4 parameters and an output schema, the description covers the core purpose, filtering options, and cost. Any missing details (e.g., error conditions, exact return format) are minor given the schema and annotations.

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 100%, so all parameters have descriptions (team1, team2, limit, season). The description mentions season filtering but does not add meaning beyond the schema's 'Season year. Omit for all-time.' It provides no extra detail on team codes or limit syntax, so it stays at the baseline of 3.

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's purpose: comparing two teams' history and specifies the outputs (recent meetings with scores, win/loss record, average margin). This differentiates it from sibling tools like get_team_stats (single team) even without naming them explicitly, but it lacks an explicit sibling disambiguation.

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 opening phrase 'Use to compare two teams' history' provides a clear when-to-use. It also mentions filtering by season or all-time, which guides parameter selection. However, it does not mention when not to use this tool or point to alternative sibling tools, so it lacks exclusions.

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